<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0607</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2026-03-18</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001993463</issuerCik>
        <issuerName>YSX Tech Co., Ltd</issuerName>
        <issuerTradingSymbol>YSXT</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002122930</rptOwnerCik>
            <rptOwnerName>Zheng Weiqiang</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>true</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>ROOM 102, BUILDING 1,</rptOwnerStreet1>
            <rptOwnerStreet2>NO. 22, HUAZHOU ROAD</rptOwnerStreet2>
            <rptOwnerCity>GUANGZHOU</rptOwnerCity>
            <rptOwnerNonUSStateTerritory>GUANGDONG PROVINCE</rptOwnerNonUSStateTerritory>
            <rptOwnerCountry>F4</rptOwnerCountry>
            <rptOwnerZipCode>510000</rptOwnerZipCode>
            <rptOwnerStateDescription>CHINA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A ordinary shares, par value US$0.0001 per share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>566772</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Wei Qiang Zheng ZWQ Holding Limited</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class B ordinary shares, par value US$0.0001 per share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>366666</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Wei Qiang Zheng ZWQ Holding Limited</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents 566,772 Class A ordinary shares and 366,666 Class B ordinary shares held by Wei Qiang Zheng ZWQ Holding Limited, a business company incorporated in the British Virgin Islands, which is wholly owned by Weiqiang Zheng. The registered address of Wei Qiang Zheng ZWQ Holding Limited is Sea Meadow House, P.O. Box 116, Road Town, Tortola, British Virgin Islands.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Weiqiang Zheng</signatureName>
        <signatureDate>2026-05-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
