Multifunctional down-the-hole drill bit

The invention discloses a multifunctional down-the-hole drill bit, relates to the technical field of geotechnical engineering mechanical equipment, solves the technical problem that the same down-the-hole drill bit in the prior art cannot adapt to two working stratums of silty soil and hard soil or silty soil and rock, and comprises a drill rod and a hammer head arranged at the front part of the drill rod, the hammer head comprises a fixed base and a conical fin structure, the top face of the fixed base is round, the width of the bottom edge of the fin structure is 1-1.5 times of the width of the top face of the fixed base, the fin structure comprises at least two fins which are connected with each other, the included angles between the fins are equal, each fin is in a right triangle shape, and the included angles between the fins are equal to the included angles between the fins. Spherical teeth are respectively arranged on the top surface of the fixed base and the tops of the fins, and each spherical tooth