The invention discloses a miniature dual microwave and millimeter wave self-load I/Q quadrature filter which comprises a directional coupler and two microwave and millimeter wave filters. Wherein the directional coupler is in self connection with a matched load and the two microwave and millimeter wave filters are each of a strip line structure. The directional coupler in self connection with the matched load comprises a surface-mounted input/output interface, a broadside coupling strip line of a dual spiral structure and the matched load in self connection with an isolation port. The two microwave and millimeter wave filters each comprise a surface-mounted output interface and a six-level parallel resonance unit achieved through the strip line structure, and the structures are achieved through the multi-layer low temperature co-fired ceramic process technology. The miniature dual microwave and millimeter wave self-load I/Q quadrature filter has the advantages of being free of any external load, capable of generating a quadrature phase, easy to debug, small in insertion loss, light, small in size, high in reliability, good in electrical performance, good in temperature stability, good in electrical performance batch consistency, low in cost and the like, and is suitable for communication of corresponding millimeter wave frequency bands, satellite communications, and other occasions and corresponding systems having strict requirements for sizes, electrical performance, temperature stability and reliability.