Dynamic response time is a key index of thyristor controlled reactor(TCR) type static var compensator(SVC) dynamic performance. Aiming to solve traditional detection problems of no unified datum time and overdependence on indirect measurement, assessment method of TCR dynamic response time based on real firing angle detection is proposed. According to a step reference signal trip generated fixed capacitor(FC) zero-crossing trip, datum time is unified. Then the response time is determined by comparing TCR real firing angle with lower limit value. The experimental result shows that this method can be effectively applied to analyse and evaluate dynamic response performance of large capacity TCR type SVC.