A new type of distributed sensor system based on Rayleigh scattering Brillouin Optical Time Domain Analysis (RBOTDA) was proposed. This system was realized in one end access fiber, which can improve the shortcomings of two end access in conventional BOTDA. Parallel structure with two EOM were used to generate pulsed light with continuous base wave. Probe light was provided by the Rayleigh scattering of the base continuous light. This avoids the interference of a variety of Stimulated Brillouin Scattering (SBS) effect and brings the higher signal to noise ratio and longer sensing distance. The dual sideband probe scheme turns the system to be highly robust against pump pulse depletion and non-local effect. The SBS function mechanism of the system was analyzed and the feasibility of the proposed method was demonstrated experimentally. The results show that the Brillouin gain spectra fit Lorenz Curve perfectly and non-local effect is suppressed effectively. The Brillouin frequency shift is 10.867 GHz and the Brillouin linewidth is about 40.21 MHz with 50 ns pulse width on the 2.4 km optical fiber at the temperature of 25℃.