The wind generation installation meets a remarkable increase in a decade in order to realize the carbon dioxide emission reduction. However, the high penetration of wind energy into the power system brings many operating challenges to the power system. Traditional system operating codes ask the generations to provide necessary support on the system frequency and voltage during the contingency. With the increased integration of wind energy into the system, some new codes are enacted to ask the wind power producer to participate in the system emergency regulation. However, the different penetration levels influence of wind energy on the system regulation have not received too much attention in the existing codes. In this paper, a code study of the wind farm transient support is conducted considering the different wind power penetration levels, in addition, some suggestions for the wind farm transient support codes are proposed. From the three control periods: wind generation participation moment, wind generation exit moment, and system fault recovery support by wind generation, the transient support capability of the wind generation under different penetration levels is studied. The case study conducted by a detailed wind farm model built in EMTDC/PSCAD provides simulation verifications to provide a guide for wind farm operators to make appropriate transient support control strategies.