A meshed catalyst based high-yield preparation and regeneration method for carbon nanotubes and hydrogen includes the following steps: step one, adding waste plastic into a low-temperature pyrolysis section, conducting slow heating, and continuously introducing nitrogen; step two, using a multilayer stainless steel mesh obtained through laminated pressing and vacuum sintering as a catalyst, introducing the volatiles into a high-temperature catalytic section, conducting a catalytic reaction under the action of a meshed stainless steel catalyst obtained through acid etching and calcination pretreatment, generating the carbon nanotubes on a surface of the catalyst, and meanwhile generating high-purity hydrogen; and step three, after temperature drop, conducting ultrasonic treatment on a stainless steel mesh after the reaction, achieving physical stripping of the carbon nanotubes from the stainless steel mesh, then placing the stainless steel mesh subjected to secondary calcination in a system for recycling, and regenerating the carbon nanotubes and the hydrogen.