In petroleum, chemical, light industry, metallurgy, building materials, paper making, textile and other industrial enterprises there is a large amount of low-grade energy a low-pressure saturated steam, these low-grade energy except for a small amount of recycling, a large number of emptying, resulting in a great waste of energy. The aim of this paper is to investigate the modelling analysis of saturated steam turbines with respect to multi-body dynamics. The paper systematically analyses methods and key technologies for the recovery and utilisation of low-value thermal energy, as well as the design, development and optimisation of specific industrial low-pressure saturated steam turbines to improve the performance of waste heat recovery systems. Energy conservation and reduction of consumption are of great importance to industrial companies. to reduce the risk of steam-induced blade corrosion. A small 100 kW waste heat recovery turbine was designed for liquid saturated steam at a flow rate of 1 tonne per hour and a pressure of 0.8 MPa. The unit is characterised by its high efficiency and small structural dimensions. This feature is intended to solve the problem of low efficiency and difficulties in recovering waste heat due to the uneven distribution of the heat source and its small size. The application site can be a small factory or a house. This paper focuses on the structural design and calibration of key turbine components, such as moving blades, impellers and cylinders. The maximum error of the hybrid model in this paper is experimentally proven to be within 3%, indicating that the hybrid model of the turbine body is consistent with the actual operating conditions and meets the engineering accuracy requirements.