In order to study the fire resistance of prestressed continuous composite beams and master the finite element simulation method, a set of two-span steel-mixed continuous prestressed composite beams were designed and tested, and the finite element model of material and geometric nonlinear forces was established by ABAQUS finite element software. By investigating the characteristics of the composite beam under high temperature, such as failure form, deflection change, reaction change at the support, curvature change of key section and internal force change of cable, comparing the test and finite element simulation results, the results show that: Under the standard heating mode, the temperature distribution of each component of the composite beam is different, and the temperature rise rate of the lower flange of the steel beam is the fastest, followed by the web, the upper flange of the steel beam, and the concrete slab. The failure form of the composite beam at high temperature shows that the mid-span deflection is too large, and the web plate and flange of the middle support are distorted. The mid-span deflection decreases gradually with increasing temperature, and the rate starts to accelerate when the temperature is about 450 degrees. The relative tension of the cable decreases first and then increases slowly with the increase of temperature. The relative reaction of the support decreases first and then increases with the increase of temperature. The nonlinear finite element simulation model of two-span prestressed continuous steel-concrete composite beams is obtained after comparison and verification, which provides technical support for further engineering.