The invention belongs to the technical field of energy collection, in particular to an MEMS electric field energy collector based on an electret. The MEMS electric field energy collector based on the electret is mainly used for collecting energy of an alternating-current electric field in a space. The MEMS electric field energy collector based on the electret comprises an insulating substrate, a piezoelectric wire, a supporting surface and the electret, wherein the piezoelectric wire is arranged above the insulating substrate in parallel, an electrostatic field composed of the electret adhering to the supporting surface provides appropriate bias for the piezoelectric wire located in the electrostatic field, sensitivity of the piezoelectric wire biased by the electrostatic field to an external electric field is greatly improved, when the piezoelectric wire vibrates due to excitation of the external electric field, a piezoelectric material carries out stress-strain due to stretching or shrinkage so that internal electric charges flow to form electrical signals, and mechanical energy can be converted into electric energy; electric field energy is collected through an external circuit connected with the piezoelectric wire. The MEMS electric field energy collector based on the electret is manufactured through the MEMS micromachining technology, electric field energy in a space is used creatively, and the collector is small in size, convenient to carry and low in cost.