NOTES RECEIVABLE, NET - THIRD PARTIES - (Schedule of Movement of Allowance for notes receivable) (Details) - CNY (¥)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
At beginning of year	¥ 0	¥ 0	¥ 0
Addition	0	0	0
Reversal	(40,662)	0	0
At end of year	182,338	0	0
ASU No. 2016-13
At beginning of year	0	0
At end of year	¥ 223,000	¥ 0	¥ 0

Amount of allowance for credit loss on financing receivable, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(4))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446

Name:	us-gaap_AllowanceForNotesAndLoansReceivableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant