The invention discloses a recombinant 
bacillus subtilis of high-yield 
pullulanase and a construction method thereof. The construction method of the recombinant 
bacillus subtilis of the high-yield comprises the following steps that an artificial 
operon BPB used for expressing the 
pullulanase is used for constructing a recombinant 
plasmid pGE-BPB; the 
nucleotide sequence of the artificial 
operon BPB is shown in the graph SEQ ID NO.4; the constructed recombinant 
plasmid pGE-BPB is converted into a 
bacillus subtilis competent cell, and through secondary recombination, a 
neutral protease gene nprE in the bacillus subtilis 
competent cell is replaced by the artificial 
operon BPB in situ. According to the recombinant bacillus subtilis of the high-yield 
pullulanase and the construction method thereof, firstly, the acidproof and heatproof pullulanase 
gene of an original 
bacterial strain is optimized, based on the 
synthetic biology method, a plurality of molecular elements capable of improving the 
gene transcriptional level are assembled into the artificial operon, and the recombinant bacillus subtilis can be obtained through construction. The recombinant 
bacterial strain can ferment to generate the high-yield pullulanase, and the 
enzyme activity each unit can reach or exceed 300 U / ml.