In this study, the anti-seismic performance test of semi-rigid composite structures with steel beam and PEC column is conducted, and four integral frame specimens with different connection types are designed. The coordinate performance of the composite structure of steel beam and PEC column is studied by application of repeated low-cycle horizontal loads, and the effect of end plate thickness, angle steel setting, bolt spacing and other factors on the anti-seismic performance of the whole frame is analyzed. The test results show that the yield mechanism of the composite structure conforms to the anti-seismic design requirements for "strong column and weak beam", and the top flange of the beam deforms seriously and forms plastic hinge, and the root of the column bends into plasticity. Increasing the thickness of the end plate and reducing the bolt spacing can increase the rotational ductility, increase the bearing limit, and improve the initial stiffness. The ductility of each frame is good, the displacement ductility coefficient is greater than 2.6, and the ductility of the frame connected by end plate is higher than that connected by angle steel. The value of the equivalent viscous damping coefficient he ranges from 0.84 to 1.14, and the anti-seismic performance of each frame is good.