The invention discloses a power electric control cabinet which comprises a cabinet body. The cabinet body is internally provided with a power firing line, a null line and a ground line, internally provided with a transformer connected with the power firing line and the null line, further internally connected with a detection ground line connected with the ground and internally provided with a detection relay and an alarm device. The ground line, the detection relay, the wiring end of the transformer and the detection ground line are sequentially connected in series for forming a detection circuit, and the wiring end of the transformer, the alarm device and a normally closed contact point of the detection relay are sequentially connected in series for forming an alarm circuit. By means of the power electric control cabinet, the ground connection situation of the electric control cabinet can be continuously detected in real time, an alarm signal can be given out under the poor ground connection situation , a clear prompt can be given to a user, and thus safe protection can be provided for the user.