Abstract: In order to get the estimating method of the ballistic limit of ultra-high molecular weight polyethylene（UHMWPE） fiber-reinforced laminates under ballistic impact,this paper proposes a 4-stage model of energy-absorbing and analyzes the actual energy-absorbing process of UHMWPE laminates with different thickness being penetrated by a 3.3 g cube fragment. The method of estimating the ballistic limit of UHMWPE laminates under high-velocity penetration is presented accordingly,which analyzes the energy distribution of UHMWPE laminates with different thickness under the extreme condition. The results show that the main energy-absorbing method of composite laminates is the absorption of shearing failure and compressing failure,as well as constructural kinetic energy and fiber tensile energy. When the thickness of laminates increases,the proportion of the first three energy sources also increases,while the fiber tensile energy absorption reduces. Overall,the ballistic limit estimated with the proposed method agrees well with the experimental data.