Teledyne QUlKLOOK ll valve online diagnosis system can diagnose valves installed on nuclear power plant pipelines without dismantling the valves. By accurately measuring the working parameters of the valves, analyzing and judging the status of the valves, it can provide guiding suggestions for maintenance. Through the valve diagnosis, the change trend of the valve state can be obtained, and the safety faults existing in the valve operation process can be discovered in a timely and effective manner, and the valves that really need to be dismantled and maintained can be found out, which can greatly reduce the maintenance cost of the valve and greatly improve the safety of the system reliability.