Based on the theory of partially coherent light, this article studies the influence of the spatial coherence of incoherent monochromatic LED light source on the generation of Bessel beam. When the partially coherent light goes through an axicon, higher-order Bessel functions appear in the light intensity distribution, and the light intensity is the linear superposition of each-order Bessel functions. Light intensity distributions are numerically simulated. The result shows that the shorter initial coherent length is, the greater the effect of high-order derivatives is, and more obvious the difference between Bessel beam and the ideal Bessel is, and that the light intensity is non-zero in dark rings and section of light distributions is fuzzier. Through an experimental setup that can regulate initial coherent length of light, nearly ideal Bessel beam is generated. The experimental results agree with theoretical analysis.