Analyze the deformation calculation of prestressed steel concrete continuous composite beams under normal service limit state. Analyze and consider the slip effect between steel and concrete, establish a simplified calculation model, and based on this, propose a calculation formula for the length of the crack zone of the concrete support and the internal force increment of the prestressed reinforcement. Provide a calculation chart for the mid span deflection of a two span prestressed continuous composite beam. The analysis results indicate that the deformation calculation formula for two span prestressed continuous composite beams has a high accuracy in calculating the internal force value of prestressed reinforcement in the normal use limit state. The deformation calculation value without considering the internal force increment of prestressed reinforcement is larger than the experimental value. The accuracy of the deformation calculation value considering the internal force increment of prestressed reinforcement has significantly improved, which is in good agreement with the experimental results and can be used as a reference for engineering design. Finally, a general method for calculating the deformation of prestressed continuous composite beams is proposed based on the formula for calculating the deformation of two span prestressed continuous composite beams