Tassel branch number is a key trait that contributes greatly to grain yield in maize (Zea mays). We obtained a classical mutant from maize genetics cooperation stock center,Teopod2(Tp2), which exhibits severely decreased tassel branch. We conducted a comprehensive study, including phenotypic investigation, genetic mapping, transcriptome analysis, overexpression and CRISPR knock-out, and tsCUT&Tag ofTp2gene for the molecular dissection ofTp2mutant. Phenotypic investigation showed that it is a pleiotropic dominant mutant, which is mapped to an interval of approximately 139-kb on Chromosome 10 harboring two genesZm00001d025786andzma-miR156h. Transcriptome analysis showed that the relative expression level ofzma-miR156hwas significantly increased in mutants. Meanwhile, overexpression ofzma-miR156hand knockout materials ofZmSBP13exhibited significantly decreased tassel branch number, a similar phenotype withTp2mutant, suggesting thatzma-miR156his the causal gene ofTp2and targetsZmSBP13gene. Besides, the potential downstream genes ofZmSBP13were uncovered and showed that it may target multiple proteins to regulate inflorescence structure. Overall, we characterized and clonedTp2mutant, and proposed a zma-miR156h-ZmSBP13 model functioning in regulating tassel branch development in maize, which is an essential measure to satisfy the increasing demands of cereals.