The invention discloses a composite process based on self-resistance heating plate connection and gas bulging forming. The composite process comprises the steps that welding and edge sealing of a blank A and a blank B are achieved by means of a resistance welding method; a gas channel is reserved between the blank A and the blank B; the blank A and the blank B are put into a mold, the power source connecting manner is changed, and the blank A and the blank B are heated to the required temperature range of forming through the resistance of the metal plates; and inert gas with the pressure P is introduced through the gas channel, and gas pressure forming of hollow pieces of the metal plates is completed under the effect of the gas pressure. According to the composite process based on self-resistance heating plate connection and gas bulging forming, a traditional box type furnace whole heating is replaced with the self-resistance heating manner, and the composite process has the beneficial effects that the heating efficiency is high, the energy consumption is small, and blank oxidization is reduced; and furthermore, the operability is high, plate connection and heating can be achieved just by changing a current loop and controlling the magnitude of the current, the design and manufacturing of corresponding technological equipment are reduced, and industrialization is facilitated.