The invention discloses a method for obtaining compact plant germplasm of maize through site-specific mutagenesis and application thereof. The method for cultivating compact plant maize comprises the step of introducing a maize genome edited carrier to target maize to obtain the compact plant maize. Compared with the target maize, the compact plant maize has the advantage that the leaf angle becomes smaller. The maize genome edited carrier contains Cas9 protein genes, sgRNA encoding genes and an RNA polymerase III recognized promoter. By the adoption of the method, maize gene editing can be achieved, the compact type maize with a straight character can be obtained, and breeding value and cultivation value are high.