In order to meet the work requirements of long-term pressure holding and rapid response of the system under unattended working conditions, the hydraulic control check valve used in the hydraulic circuit under long-term pressure holding conditions is needed to have higher reliability. Therefore, a hydraulic system was designed to verify the reliability of the hydraulic control check valve in the long-term pressure holding. The corresponding test data acquisition system was also built. In the short-term and long-term experimental conditions, the pressure holding performance and the open reliability after long standby of the hydraulic control check valve were tested. The reliability ability and technical status change under the long-term pressure holding state of the valve were obtained. It provided data supports for reliability promotion and improvement of the hydraulic check valve subsequently.