Continue laser or pulse laser is combined with the pulse gas metal arc welding (GMAW) to study the dynamic interaction behavior of laser plasma and arc plasma at different hybrid welding modes. The study results show that the pulse laser+pulse GMAW hybrid welding mode can achieve a higher penetration than continuum laser+pulse GMAW hybrid welding under a low average power condition. It is found that if the peak time of the laser pulse has a phase shift with the arc current pulse rise period, the phenomenon of rapid expansion of the plasma at this transient moment can be suppressed, thus improve the transmission of laser energy.