The invention provides a preparation method of high-purity spherical full-pore silica gel particles. The method is carried out according to the following steps of: hydrolyzing, polymerizing in advance, distilling, preparing a water phase, preparing an oil phase, synthesizing particles and grading. In the invention, ethyl orthosilicate is used as a raw material, silica sol with high concentration (which is greater than 90wt%) is obtained by hydrolyzing and polymerizing in advance under an acidic condition, and the yield is enhanced; the formula of emulsion is optimized through a method of emulsion polymerization by adopting a compounded surfactant, the stability of the emulsion and the monodispersity of liquid drops are enhanced, the agglomeration and the shape deformation of the particlesare avoided, and water is adopted as a reaction medium, which adapts to the requirement of environmental protection; in the preparation of the particles, a pore structure is naturally formed without burning organic components at high temperature to obtain a porous structure, which is simple, convenient and effective and protects the environment; the entire method has simple procedure, excellent repeatability and low cost; and the obtained material has high purity, good mechanical strength, uniform particle diameter, controllable size and narrow and controllable pore diameter distribution.