The invention relates to the technical field of gene engineering, in particular to application of tomato WRKY37 protein in regulation and control of leaf aging resistance of tomatoes and improvement of tomato yield. The tomato WRKY37 protein is found to be capable of regulating and controlling the leaf aging resistance of tomatoes and regulating and controlling the fruit yield of the tomatoes. In practical application, the WRKY37 gene in the tomato can be knocked out through a gene editing means, and expression of the WRKY37 protein is inhibited, so that a tomato strain with higher leaf aging resistance is obtained; or the slwrky37-KO plant is hybridized with other tomato varieties to cultivate an anti-aging and high-yield tomato variety. The tomato WRKY37 gene is mutated by utilizing a CRISPR-Cas9 genome site-directed editing system, a high-yield tomato strain is created, the leaf aging resistance of the tomato strain is remarkably improved, the yield is also remarkably improved, and the invention has important application value.