The traditional leveling method for wheeled crane outrigger has some defects,including big error,poor accuracy and prone to weak leg,etc.Herein,taking “H” type crane outrigger as an example,an automatic leveling system design scheme and leveling strategy for outrigger were proposed by using electro-hydraulic proportion and sensor technology.Trial production,test and market inspection show that this design meets the use requirements.It provides reference for the leveling design of the wheeled cranes.