A pedestrian warning device, comprising a warning device body having a cavity and an open end portion, and a sound generating device mounted inside the cavity, wherein the pedestrian warning device further comprises a grille cover arranged on the end portion of the warning device body, characterized in that the grille cover comprises at least two grille layers (31, 32) spaced at intervals from inside to outside, each of the grille layers (31, 32) comprises a plurality of crossbeams (31a, 32a), the crossbeams (31a, 32a) are arranged at intervals so as to form gaps (31b, 32b) to enable gas to flow between adjacent crossbeams (31a, 32a), and a width of the gaps (31b, 32b) is not greater than a width of the crossbeams (31a, 32a), and the crossbeams (31a, 32a) of adjacent grille layers (31, 32) are interleave with each other; wherein the grille cover comprises an inside grille layer and an outside grille layer spaced up and down, the inside grille layer is located below the outside grille layer, and the two layers (31, 32) have a height difference; the inside grille layer is composed of a plurality of mutually parallel crossbeams; the outside grille layer is composed of a plurality of mutually parallel crossbeams; the crossbeams of the inside grille layer and the crossbeams of the outside grille layer are interleave with each other so that each gap of the inside grille layer directly faces one crossbeam of the outside grille layer, respectively, and each gap of the outside grille layer directly faces one crossbeam of the inside grille layer, respectively; an extension direction of the crossbeams of the inside grille layer and an extension direction of the crossbeams of the outside grille layer are consistent, outer surfaces of the respective crossbeams of the inside grille layer have reinforcing ribs extending outwards, outer ends of the reinforcing ribs are located inside the outside grille layer, and the reinforcing ribs are located in the middle position of the crossbeams and directly face the gaps of the outside grille layer; wherein, the grille cover further comprises a housing arranged around the grille layers (31, 32), the grille layers (31, 32) are fixedly connected in the housing, and the housing is connected to the one end portion of the warning device body, an inner surface of the housing has an arc transition section. the grille cover comprises at least two grille layers (31, 32) spaced at intervals from inside to outside, each of the grille layers (31, 32) comprises a plurality of crossbeams (31a, 32a), the crossbeams (31a, 32a) are arranged at intervals so as to form gaps (31b, 32b) to enable gas to flow between adjacent crossbeams (31a, 32a), and a width of the gaps (31b, 32b) is not greater than a width of the crossbeams (31a, 32a), and the crossbeams (31a, 32a) of adjacent grille layers (31, 32) are interleave with each other; wherein the grille cover comprises an inside grille layer and an outside grille layer spaced up and down, the inside grille layer is located below the outside grille layer, and the two layers (31, 32) have a height difference; the inside grille layer is composed of a plurality of mutually parallel crossbeams; the outside grille layer is composed of a plurality of mutually parallel crossbeams; the crossbeams of the inside grille layer and the crossbeams of the outside grille layer are interleave with each other so that each gap of the inside grille layer directly faces one crossbeam of the outside grille layer, respectively, and each gap of the outside grille layer directly faces one crossbeam of the inside grille layer, respectively; an extension direction of the crossbeams of the inside grille layer and an extension direction of the crossbeams of the outside grille layer are consistent, outer surfaces of the respective crossbeams of the inside grille layer have reinforcing ribs extending outwards, outer ends of the reinforcing ribs are located inside the outside grille layer, and the reinforcing ribs are located in the middle position of the crossbeams and directly face the gaps of the outside grille layer; wherein, the grille cover further comprises a housing arranged around the grille layers (31, 32), the grille layers (31, 32) are fixedly connected in the housing, and the housing is connected to the one end portion of the warning device body, an inner surface of the housing has an arc transition section.