The invention discloses a structure for capacitor detection of a capacitive micro-mechanical accelerometer. Both a first mass block and a second mass block are connected with a third mass block, electric isolation is conducted on the first mass block and the second mass block by the third mass block, a locomotive pole plate of a detection capacitor C1 and a locomotive pole plate of a detection capacitor C3 are connected with the first mass block, a locomotive pole plate of a detection capacitor C2 and a locomotive pole plate of a detection capacitor C4 are connected with the second mass block, a static pole plate of a detection capacitor C1 and a static pole plate of a detection capacitor C2 are connected with an external pin A through leads, and a static pole plate of a detection capacitor C3 and a static pole plate of a detection capacitor C4 are connected with an external pin B through leads. According to the structure, capacitor differential detection of the capacitive micro-mechanical accelerometer can be achieved without an external matched capacitor, and the matchability is better without the external matched capacitor, so that the technical effect of performance deterioration of the capacitive micro-mechanical accelerometer caused by mismatching of matched capacitor amount and the change of the matched capacitor is avoided.