Prefabricated steel-concrete composite frames are increasingly applied in engineering day by day.However，research on their anti-collapse performance is less reported.To investigate their dynamic collapse perfor-mance，two reduced-scale prefabricated composite frame substructures were designed and tested by dynamically removing a column in this paper.Collapse behaviors of such frame structures under different load conditions were studied，and the effect of the division of precast concrete（PC）slabs on the dynamic collapse behaviors was also assessed.Then，a calculation model of the equivalent dynamic increase factor（DIF）of collapse load was built based on the experimental results for prefabricated composite frames.The results show that under the effects of one time collapse load（30 kN）and twice collapse load（60 kN），the primary structural damage for prefabricated steel-concrete frame substructures is the cracking of concrete slab at the beam ends close to the side column.After the middle column failed，the residual structures still have the superior load-bearing capacity and overall stiffness.The structures will not collapse under the two load conditions.The prefabricated composite frames are subjected to a greater impact effect under the same collapse load compared to the composite frames using cast-in-situ concrete.Division of the PC slabs slightly affect the dynamic characteristics of the composite frame substructures.However，it will lead to the increase of the strain dynamic increase factors of the steel girders and the longitudinal slab reinforcement.The increase factors of vertical displacement at the failed columns vary between 1.38 and 1.65 for the two substructures，and the dynamic increase factors of strain are even greater than 2.0 in some cases.The calculation model of the equivalent DIFs of collapse load for prefabricated composite frames developed based on the experimental results can provide a reference for the revision of the collapse load when the static collapse analysis is conducted.The calculated DIF of collapse load based on this model is conservative.