v3.26.1
Cover
 12 Months Ended
Mar. 31, 2026
shares
Document Information [Line Items]  
Document Type 20-F
Document Registration Statement false
Document Annual Report true
Document Transition Report false
Document Financial Statement Error Correction [Flag] false
Document Shell Company Report false
Entity Interactive Data Current Yes
Document Accounting Standard U.S. GAAP
ICFR Auditor Attestation Flag false
Amendment Flag false
Document Period End Date Mar. 31, 2026
Document Fiscal Year Focus 2026
Document Fiscal Period Focus FY
Entity Registrant Name Lianhe Sowell International Group Ltd
Entity Central Index Key 0002004024
Entity File Number 001-42579
Entity Incorporation, State or Country Code E9
Current Fiscal Year End Date --03-31
Entity Well-known Seasoned Issuer No
Entity Voluntary Filers No
Entity Current Reporting Status Yes
Entity Filer Category Non-accelerated Filer
Entity Shell Company false
Entity Emerging Growth Company true
Entity Ex Transition Period false
Entity Address, Address Line One 15th Floor, Sannuo Smart Building
Entity Address, Address Line Two No. 3388 Binhai Ave, Binhai Community
Entity Address, Address Line Three Nanshan District
Entity Address, City or Town Shenzhen
Entity Address, Country CN
Entity Address, Postal Zip Code 00000
Title of 12(b) Security Class A Ordinary Shares, par value $0.0016
Trading Symbol LHSW
Security Exchange Name NASDAQ
Class A Ordinary Shares  
Document Information [Line Items]  
Entity Common Stock, Shares Outstanding 3,250,000
Class B Ordinary Shares  
Document Information [Line Items]  
Entity Common Stock, Shares Outstanding 62,500
Business Contact  
Document Information [Line Items]  
Contact Personnel Name Yue Zhu
Entity Address, Address Line One 15th Floor, Sannuo Smart Building
Entity Address, Address Line Two No. 3388 Binhai Ave, Binhai Community
Entity Address, Address Line Three Nanshan District
Entity Address, City or Town Shenzhen
Entity Address, Country CN
Entity Address, Postal Zip Code 00000
City Area Code +86
Local Phone Number 400-616-9629