Aiming at abundent input/output（ I/O） resource and parallel processing characters of field programmable gate array（ FPGA） is of meaning for large-scale compensating system for Si piezoresistive pressure sensor and increasing its compensation efficiency is significative

a compensated system design scheme is proposed and aiming at nonlinear error of sensor input and output

design 32 bit single-precision floating point unit（ FPU） for realizing the polynomial curve fitting methods

Verilog language is used in Xilinx ISE to implement logic design

simutation and synthesis of FPGA. The results show that the polynomial fitting algorithm which can be realized in FPGA is effective

and it can be used for calibration of nonlinear system and has application value.