ORGANIZATION AND BASIS OF PRESENTATION (Details)	Dec. 31, 2017
Express Test Corporation (Dormant)
Ownership	100.00%
Trio-Tech Reliability Services (Dormant)
Ownership	100.00%
KTS Incorporated, dba Universal Systems (Dormant)
Ownership	100.00%
European Electronic Test Centre (Operation ceased on November 1, 2005)
Ownership	100.00%
Trio-Tech International Pte. Ltd
Ownership	100.00%
Universal (Far East) Pte. Ltd
Ownership	100.00%	[1]
Trio-Tech International (Thailand) Co. Ltd
Ownership	100.00%	[1]
Trio-Tech (Bangkok) Co. Ltd. (49% owned by Trio-Tech International Pte. Ltd. and 51% owned by Trio-Tech International (Thailand) Co. Ltd.)
Ownership	100.00%
Trio-Tech (Malaysia) Sdn. Bhd. (55% owned by Trio-Tech International Pte. Ltd.)
Ownership	55.00%
Trio-Tech (Kuala Lumpur) Sdn. Bhd. (100% owned by Trio-Tech Malaysia Sdn. Bhd.)
Ownership	55.00%
Prestal Enterprise [Member]
Ownership	76.00%
Trio-Tech (Suzhou) Co. Ltd.
Ownership	100.00%	[1]
Trio-Tech (Chongqing) Co. Ltd. SHI International Pte. Ltd.
Ownership	100.00%	[1]
SHI International [Member]
Ownership	55.00%
PT SHI Indonesia (100% owned by SHI International Pte. Ltd)
Ownership	55.00%
Trio-Tech (Tianjin) Co. Ltd.
Ownership	100.00%	[1]

[1] 100% owned by Trio-Tech International Pte. Ltd.