The purpose of operational test of high power thyristor valve is to verify whether the valve meets design criteria and standard requirements

and ensure the valve to satisfy its function in normal or fault condition without damage or influencing the grid system. The synthetic test circuit method has become the preferred testing method due to its advantages of flexible access mode

being environment-friendly

energy saving

and so on.Based on the synthetic test circuit

this paper introduces the implementation methods of special operation test items of thyristor valve

and compares the difference among different methods. It is concluded that for intermittent direct current test

the current source method has good equivalence

while the voltage source method can suffer severity and has good adjustability of duration time of zero current; and for temporary under-voltage test

the voltage source method is better than the water-resistance method in equivalence and controllability. In addition

this paper introduces the failure phenomenon that may appear in the fault current test

and analyzes the cause of the failure. This study may provide a reference for manufacturing and testing thyristor valves.