The invention discloses a device and method for detecting the performance of a DNA by using a ZnO nanorod to enhance an optical addressing potential sensor. The device includes a Faraday shielding box, a loading table, a semiconductor laser, an LAPS sensor, a constant voltage device, a phase-locked amplifier, an acquisition card, and a computer. The method includes the steps of making a LAPS chip,modifying the surface of the LAPS chip with the ZnO nanorod, modifying the surface of the LAPS chip with a probe chain DNA, scanning an I-V curve; placing a target DNA in a detection cavity, scanningthe I-V curve, and comparing the performances of the modified and unmodified ZnO nanorods. Label-free detection of the DNA is realized, and the advantages that the time is short, the cost is low, operation is convenient, three-dimensional sites are provided for DNA hybridization, and sensitivity is high are achieved.