Fiber glass reinforced bonded flexible pipe (FGRFP) is one kind of new type composite pipe. However, the mechanical properties of FGRFP are not so clearly at present. Therefore, this article aims at studying the buckling pressure of FGRFP under external pressure by using external pressure test, numerical method and finite element method. Three kinds of buckling pressure have been obtained by using three methods as aforesaid. According to compare the buckling pressure of three methods, the relative error of the numerical method and the finite element method relative to external pressure test ranges from 4.09% to 14.51%. According to the result of finite element method, the first layer’s stress at the topside of FGRFP’s cross section and the final layer’s stress at the horizontal position of FGRFP’s cross section is the max stress. The numerical method and finite element method came up with in this article can be used to analyze the buckling pressure of FGRFP. These methods can also provide a guidance to pipeline engineers to design and production of FGRFP.