The growth stages of science and technology enterprises are divided into four stages: start-up stage, growth stage, mature stage and recession stage. The characteristics of each growth stage and the main risks faced by science and technology enterprises are analyzed, and the differentiated support policies and measures formulated by developed countries according to the characteristics of different development stages of science and technology enterprises are studied. Finally, puts forward some countermeasures and suggestions for formulating policies to promote the development of science and technology enterprises in China.