A kind of Fabry-Perot optical fiber humidity sensor is fabricated by normal single-mode optical fiber and Graphene Quantum Dots.By the established experimental system, the humidity response experiments were carried out in the relative humidity range of 11% RH ~85% RH. The sensitivity was 0.560 6 nm/%RH with 0.999 47 linearity at humidity rising, and 0.565 5 nm/%RH sensitivity with 0.999 36 linearity at humidity falling. The experimental results showed that the humidity sensor has high humidity response sensitivity, good linear response characteristics and measurement repeatability. Furthermore, the temperature responding characteristic is also experimentally investigated. The good linear temperature responding results are got with 0.035 nm/℃ sensitivity, 0.012 41 residual sum of squares, 2.305×10^-4 sensitivity stand error. The humidity response sensitivity is about 17 times of temperature response. Typical tests are given for dynamic response characteristics. The dynamic response data of interference spectrum wavelength drift under 43% RH showed fast dynamic response characteristic. The response time and recovery time were 6.5 s and 9.0 s respectively. The research results provide a beneficial exploration for developing low cost, easily fabricated and high sensitive optical fiber humidity sensor.