The invention provides an SNP (single nucleotide polymorphism) typing detecting method for utilizing a locking-type probe for rolling ring amplification. At first, the locking-type probe and an amplification primer are designed, then the designed locking-type probe is phosphorylated, then a locking-type probe cyclization reaction is carried out, an enzyme digestion reaction is adopted for digesting an uncyclized locking-type probe and genomic DNA to obtain a cyclized locking-type probe, the cyclized locking-type probe is subjected to a rolling ring amplification reaction, a reactant obtained through the rolling ring amplification reaction is taken and subjected to 1% agarose gel electrophoresis detection, and the gene type of SNP can be judged through an electrophoresis detecting result. According to the method, SNP typing detection can be directly carried out on biological samples like peripheral blood, the genomic extraction process is omitted, the operation steps are greatly reduced, detecting time is greatly shortened, cost is saved, the risk of cross infection of operators is reduced, the detecting method has great popularization prospects, and the detecting result is accurate and sensitive.