The invention discloses a diamond-impregnated bit with double cutting structures, belonging to the technical field of drilling equipment for petroleum and natural gas, mine engineering, building foundation engineering construction, geology, hydrology and the like, and solving the problems in the prior art that a diamond-impregnated bit with a single cutting structure is short in service life in the complex stratum which is difficult to be drilled and thus adverse effects on geological exploration are caused. The diamond-impregnated bit comprises an API joint and a bit body connected with the API joint, wherein a center water channel, a plurality of blades and water channels between two adjacent blades are arranged on the bit body; double cutting structure impregnated A1 type teeth, impregnated A type teeth, impregnated B type teeth, impregnated C type teeth and double cutting structure impregnated A2 type teeth are arranged on the upper surfaces of the blades; large granular natural diamonds are impregnated on the cutting surfaces of the double cutting structure impregnated A1 type teeth and the double cutting structure impregnated A2 type teeth, and artificial small granular diamonds are uniformly and orderly arranged in the double cutting structure impregnated A1 type teeth and the double cutting structure impregnated A2 type teeth; and small granular diamonds are arranged in the impregnated A type teeth, the impregnated B type teeth and the impregnated C type teeth. The diamond-impregnated bit disclosed by the invention is used for drilling.