For the study of degradation in mechanical properties of stud connectors in steel-concrete composite structure after fatigue loads，a total of 11 specimens of stud connectors were performed in three series based on the standard push-out test method． They are static load test， fatigue test and static test under a certain fatigue loading
cycle number respectively． The static bearing capacity and fatigue life of the stud specimens were obtained． Based on this， the change rules of mechanical properties for push-out specimens such as shear bearing capacity，shear stiffness and ductility were analyzed after different fatigue load cycles． Finally，a loadslip constitutive model for the
studs consideration degradation of mechanical properties was established． The results show that the stud connectors show three different section failure characteristics in static tests，complete fatigue tests and incomplete fatigue tests;
various residual mechanical indexes for the stud specimens show a nonlinear degradation under fatigue loading and the degradation trend is significant; the established stud loadslip constitutive model is simple in form and expedient
to use． The calculated values are quite agreeable to the experimental ones．
