The utility model relates to a multifunctional lightning protection device for a single-phase intelligent electric meter, which is characterized in that a piezoresistor R1 and a piezoresistor R2 are connected in series and then connected with a transient voltage suppression diode TVS4 in parallel, two ends of the piezoresistors R1, R2 are connected to an outgoing line L and an outgoing line N respectively, a gas discharge tube GDT is connected at a common end of the piezoresistor R1 and the piezoresistor R2, and the other end of the gas discharge tube GDT is grounded; a transient voltage suppression diode TVS2 and a transient voltage suppression diode TVS3 are connected in series and then connected with a transient voltage suppression diode TVS1 in parallel, two ends of the transient voltage suppression diode TVS2 and the transient voltage suppression diode TVS3 are connected to an outgoing line A and an outgoing line B respectively, a common end of the transient voltage suppression diode TVS2 and the transient voltage suppression diode TVS3 is grounded, and the outgoing line A and the outgoing line B are connected to a wiring terminal A and a wiring terminal B of an RS485 of the single-phase intelligent electric meter respectively in parallel, thereby forming an effectively protection layer for lightning, and avoiding the single-phase intelligent electric meter from being destroyed by lightning.