The invention discloses a sporisorium reilianum PCR detection kit and a preparation method thereof. According to sporisorium reilianum genome, specific amplimer is designed, and the sporisorium reilianum PCR detection kit is made up and planned to apply to field detection. The kit can be used to accurately and quickly identify whether sick maize seedlings with symptoms of dwarfness, dwarfing bunch type, multiple-tiller type and the like are affected by sporisorium reilianum, and also used for molecular identification of sporisorium reilianum. The kit offers basis to the field detection, prediction and forecast of sporisorium reilianum and has significant social meaning as well as broad application prospect.