A molecular cloning technology based on long primers and PCR has the advantages of simple operation, high efficiency and low cost. With the emergence of high-fidelity DNA polymerase, a molecular cloning method based on the PCR is more and more widely used. The invention relates to a chimera establishment and fragment insertion based molecular cloning strategy which is named as MP cloning (mega primercloning) for the first time. The method includes the following steps that 1, PCR amplification is conducted on the long primer; 2, second round of long primer involved PCR amplification is performed; 3, a PCR product is subjected to DpnI digestion and is transformed into a competence state of escherichia coli. The MP cloning efficiency can be remarkably improved through PCR product purification. Experiments show that the method is a simple and effective molecular cloning tool.