The invention discloses a method for identifying whether a time-lapse seism is implemented or not, comprising the following steps of obtaining an energy variation difference of seismic effective signals caused by reservoir parameter variation; obtaining a noise level in actual seismic resources; comparing the energy variation difference with the noise level, if the energy variation difference is larger than the noise level, showing that the time-lapse seism can be implemented. Through result comparison of simulation energy variation and signal to noise ratio analysis, a gas field in the embodiment of the invention can be considered that the time-lapse seism can be implemented at present because the energy variation (13.3 percent) of the seismic effective signals caused by the reservoir parameter variation such as pressure dropping and the like is far higher than the noise level of a region.