The present application discloses a method for producing piperonal by using a recombinant engineered bacterium co-expressing trans-anethole oxygenase and formate dehydrogenase, and an engineered bacterium thereof, including constructing a formate dehydrogenase gene fdh and trans-anethole oxygenase gene tao or trans-anethole oxygenase mutant gene co-expression recombinant vector; inductively expressing recombinant genetically engineered bacterium; and producing piperonal by using the recombinant genetically engineered bacterium. 15.91 g/L of piperonal with a transformation rate of 79.55% and a time-space transformation rate of 2.27 g/L/h can be finally obtained during catalysis, and the yield is significantly improved compared with the existing piperonal, thereby being more conducive to the smooth realization of industrial production.