The invention discloses a miniature high-temperature and high-pressure electric rotary valve. The miniature high-temperature and high-pressure electric rotary valve comprises a cylindrical valve body, a valve core, a valve rod and a limiting connecting shaft, wherein valve seat holes are symmetrically formed in both sides of a valve core hole in the valve body, floating valve seats are arranged in the valve seat holes, the floating valve seats are matched with the valve core through curved surfaces, a port P, a port A and a port B are formed in the right end of the valve body, the three oil ports are all axially formed and are positioned in the same end surface, a part, which is communicated with the port P, of the valve core forms a cavity P, parts, which are respectively communicated with the port A and the port B, of the two floating valve seats form a cavity A and a cavity B, and the valve core is driven to reverse leftwards or rightwards by a motor, so that the port A is communicated with the port A or the port B to form a two-position three-way reversing valve. The miniature high-temperature and high-pressure electric rotary valve has the advantages of small size, compact structure and reliable sealing performance and is compatible with the small installation space of an annular pipeline, the reliable reversing of an oil system can be guaranteed, and the miniature high-temperature and high-pressure electric rotary valve can be applied in high-temperature and high-pressure severe environments such as power plants, petroleum and natural gas exploitation and the like.