The invention discloses a method for synthesizing an SAPO-35 molecular sieve by double template agents, and belongs to the technical field of SAPO-35 molecular sieve synthesis methods, wherein the method specifically comprises the following steps: taking a mixture of N-methyldiethanolamine and hexamethyleneimine as a template agent, and adding a silicon source, an aluminum source and a phosphorussource to prepare reactant gel; and synthesizing the SAPO-35 molecular sieve from the reactant gel under a hydrothermal crystallization condition. According to the method, the mixture of N-methyldiethanolamine and hexamethyleneimine is used as the template agent, the conventional phosphorus source, aluminum source and silicon source can be used as the raw materials, the pure-phase SAPO-35 molecular sieve with a large specific surface area is synthesized under the hydrothermal condition, and the synthesis cost is reduced.