The invention relates to a method and a device for simulating faults of a zirconia-type oxygen sensor for an electronic injection engine. The oxygen sensor (comprising a front oxygen sensor or a rear oxygen sensor or both the oxygen sensor and the rear oxygen sensor) for the electronic injection engine can generate independent fault-simulating modes, such as upper-limited voltage upward bias, upper-limited voltage downward bias, lower-limited voltage upward bias, lower-limited voltage downward bias, time response delay, rising edge rising slope change and falling edge falling slope change andmixed fault-simulating modes mixing the four fault modes of upper-limited voltage bias, lower-limited voltage bias, time response delay and slope change in any proportion so that fault simulation signal output is further accordant with practical fault signal output of the oxygen sensor, and the development and the authentication of an OBD system and the needs for other related search are facilitated.