DDZH hydraulic elevator is center latch elevator. Through changing the bushing, it can handle drilling pipe, drill collar, casing and tubing and uses the hydraulic control system, which makes the operation more convenient, effectively reduces the workers’ labor intensity and improves the work efficiency; it can also realize remote control and make the use safer and more reliable. The products shall be designed and manufactured according to the requirements in API Spec 8C Specification for Drilling and Production Hoisting Equipment.