Abstract: In order to study the self-healing and frost resistance performance of cracked ultra-high performance concrete (UHPC) in service, UHPC specimens with hybrid steel fibers were pre-loaded to the tensile strain level of 0.05% and 0.1%, respectively, cured in water for 28 days and then used for performing 300 freezing and thawing cycles experiment. The indexes including uniaxial tensile property, characteristics of crack, mass and ultrasonic pulse velocity (UPV) were utilized to comprehensively evaluate the self-healing and frost resistance performance. Meanwhile scanning electronic microscope and energy disperse spectroscopy (SEM-EDS) were adopted to analyze microstructure and self-healing products. The results show that: after 28 days water-curing, the specimen with pre-loaded strain of 0.05% exhibits better self-healing, in which the tensile strength, tensile strain and strain energy are higher than those of the reference specimen, and all surface cracks close; The parameters of tensile properties of the specimens with pre-loaded strain of 0.1% are lower compared to the reference specimen, with a partially healed maximum crack (the width of 69 μm). After 300 freezing and thawing cycles, the initial cracking strength and tensile strength of two types of pre-damaged specimens further increase, while both the tensile strain and strain energy show the decrease trend. The variation of relative mass and UPV can well reflect the secondary-hydration effect of two specimens. The results of SEM-EDS demonstrate that, the fiber-matrix bonding near crack is stronger; The healing products are mainly Ca(OH)₂ and CaCO₃ on the surface of crack, and calcium silicate hydrated (C-S-H) gel in the inner side of crack.