Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 23, 2022	Jun. 30, 2021
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity File Number	001-38273
Entity Registrant Name	ACM Research, Inc.
Entity Central Index Key	0001680062
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3290283
Entity Address, Address Line One	42307 Osgood Road, Suite I
Entity Address, City or Town	Fremont
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94539
City Area Code	510
Local Phone Number	445-3700
Title of 12(b) Security	Class A Common Stock, $0.0001 par value
Trading Symbol	ACMR
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,980.6
Auditor Firm ID	1818
Auditor Name	BDO China Shu Lun Pan Certified Public Accountants LLP
Auditor Location	Shenzhen, China
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		17,883,192
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,695,604