The utility model relates to a bridge load response frequency conversion acquisition instrument comprising an AD converter, the AD converter carries out analog-to-digital conversion on vehicle identification classification signals and then transmits the signals to an FPGA connected with a single-chip microcomputer, and the single-chip microcomputer transmits control signals to the FPGA; an addresslatch and a memory in the FPGA are connected with a data port of the single chip microcomputer through a data bus, an address latch port is connected with the address latch, and the address latch transmits a control signal in the single chip microcomputer to the memory; a chip selection signal port and a read gating port of the single-chip microcomputer are connected with the memory through the NOR gate, the starting signal port transmits a starting signal to the address counter, and the address counter transmits an ending signal to a conversion ending signal port of the single-chip microcomputer after counting is completed; a clock signal is transmitted to the address counter and the AD converter after being processed by the frequency dividing circuit, and is transmitted to the memory for storage through the NOT gate. According to the utility model, frequency conversion sampling can be realized, data redundancy is reduced, and distortionless recovery of signals is ensured.