Taken the jack-up offshore wind turbine installation platform with leg encircling crane as an example, the influence of Rack Phase Difference (RPD) of trussed pile leg on crane operation lifting load is studied. The calculation principle is expounded, the finite element model is established, and the influence of crane boom angle on RPD and RPD on crane operation lifting load is calculated and analyzed. The results show that the RPD values should be strictly controlled before the crane full-circle slewing operation to ensure the platform operation safety.