The invention provides a waste heat recovery thermodynamic system. The waste heat recovery thermodynamic system comprises a container, a main conveying pipeline, a face type temperature reducer, an automatic flow adjustment valve, a fluid input branch and a fluid output branch, wherein the container is provided with a containing space for containing liquid, the main conveying pipeline is arranged outside the container, the face type temperature reducer is arranged in the containing space and provided with an inlet and an outlet end, the inlet end and the outlet end are both communicated with the outside of the container, the automatic flow adjustment valve is arranged on the main conveying pipeline and can automatically adjust the flow of the main conveying pipeline, one end of the fluid input branch is communicated with the inlet end of the face type temperature reducer, the other end of the fluid input branch is communicated with the main conveying pipeline connected with the inlet end of the automatic flow adjustment valve, one end of the fluid output branch is communicated with the outlet end of the face type temperature reducer, and the other end of the fluid output branch is communicated with the main conveying pipeline connected with the outlet end of the automatic flow adjustment valve. The face type temperature reducer is arranged in the container, so that the purposes of saving space and recovering the heat inside the system are realized.