Fiber-optic surface plasmon resonance sensor (SPR) plays an important role in the fields of high sensitivity sensor and online real time monitor. We propose a novel six-fold symmetric photonic quasi-crystal fiber SPR sensor with two large semi circular channels. Its sensing properties and influence of fiber structure are simulated numerically by the finite element method. Numerical results demonstrate that its highest sensitivity can reach up to 26400 nmRIU-1, and the measuring range is 1.25-1.331. The novel quasi-crystal fiber SPR sensor, which has characteristics of large measuring range, high sensitivity, mode loss spectrum with less interference peak, design and optical path flexibility, are used widely for biochemical detection, public safety, environmental pollution monitoring and high sensitivity sensor.