The invention provides a bonnet of a thermoplastic composite material and a making method of the bonnet. The bonnet comprises an outer plate, a honeycomb core material and an inner plate, the outer plate and the inner plate are continuous fiber-reinforced thermoplastic resin-based composite materials, and the inner plate is provided with a function accessory mounting hole. The making method of thebonnet comprises the steps that the outer plate and the inner plate are made through a thermoplastic resin monomer in-situ polymerization wet-process compression molding formation technology, a gap part of a non-fitting face of the outer plate and the inner plate is filled with the honeycomb core material, and the outer plate, the honeycomb core material and the inner plate are bonded or welded through structure glue to form a bonnet assembly structure. According to the bonnet, the thermoplastic resin monomer in-situ polymerization wet-process compression molding technology is adopted for solving the problems that the flexibility of a traditional thermoplastic composite material technology is poor, and formation of products of complex structures such as bonnets cannot be achieved. The made vehicle bonnet is high in structural strength and rigidity and good in collision energy-absorption performance, the demands of vehicle safety performance and pedestrian protection can be met, the formation efficiency is high, the cost is low, and after the service life, the material can be recycled.