Abstract: This paper makes the single event sensitivity evaluation of SRAM-based FPGA designs by using the medium-energy protons accelerated by the CYCIAE-100 cyclotron, Beijing Radioactive Ion-beam Facility. The device(DUT) is a typical SRAM based FPGA (Field-Programmable Gate Array). The intrinsic SEU cross sections are obtained, and the ratio of the upsets to the function errors for a certain application are compared with those acquired by using the proton irradiation facility of Paul Scherrer Institut(PSI), Switzerland. A two-stage method for the single event sensitivity evaluation is proposed for FPGA applications, by which the functional errors in orbit can be estimated. The CYCIAE-100 can provide long-range high-energy protons and will play an important role in the single event sensitivity evaluation especially for flip-chip packaged devices.