The invention discloses a high-selectivity formaldehyde gas-sensitive material and a preparation method and application thereof. The material is prepared from lanthanum nitrate, ferric nitrate, citric acid, dispersing agent, doping metal ions, template molecules, functional monomer and initiator according to the molar ratio of 1 to 1 to 0.05-1.5 to 0.001-0.1 to 0.001-0.05 to 0.1-0.4 to 0.05-0.8 to 0.1-0.5. The preparation method includes the steps of solution mixing, microwave reacting, ultrasonic vibrating, molecule printing, drying, grinding, sintering and the like. The application is application of the high-selectivity formaldehyde gas-sensitive material in preparation of a formaldehyde gas sensor. The raw materials and ratio for preparing lanthanum ferrite base molecularly imprinted polymers are provided first, the method for preparing the lanthanum ferrite base molecularly imprinted polymer formaldehyde gas-sensitive material is provided on the basis of the provided raw materials and the provided ratio, and the lanthanum ferrite base formaldehyde gas-sensitive material high in sensitivity and selectivity and low in working temperature is obtained.