The invention relates to the technical field of cryocoolers, in particular to a mixed cycle cryocooler. The mixed cycle cryocooler comprises an air compression unit and a first refrigerating unit connected with the first air suction valve air compression unit. A second refrigerating unit is arranged on the first air suction valve first refrigerating unit in parallel. According to the mixed cycle cryocooler, a stirling cryocooler or a stirling pulse tube cryocooler is used for precooling a JT throttling refrigerating machine; a single oilless linear compressor is used for generating cyclic pressure fluctuation and is used in cooperation with a one-way valve to generate high and low-pressure air, wherein a multistage stirling cryocooler is driven through the cyclic pressure fluctuation; a single compressor is used for generating cyclic alternating flow and high and low-pressure driving unidirectional flow; through the advantages of high efficiency and high power density of the stirling cycle in a warm area above liquid hydrogen and the advantages of high efficiency, large cold capacity, high reliability and no moving parts of a helium throttling refrigerating machine, the high-efficiency compact moving-part-free cryocooler operating in a hydraulic helium warm area is formed.