The invention puts forward a boom system control method, a boom control system and a boom device. The boom system control method comprises the following steps: acquiring the actual support state data of each support leg, and determining the allowed amplitude angle range or scale length range of each boom section of a boom system at different rotation angles according to the actual support state data of each support leg; detecting the amplitude angle or scale length of each boom section; and making each boom section move within the allowed amplitude angle range or scale length range. According to the method, the allowed amplitude angle range or scale length range of each boom section is determined before the boom system moves, so that during movement of each boom section of the boom system, there is no need to calculate the center of gravity of the entire vehicle constantly, and there is only the need to judge whether the amplitude angle or scale length of each boom section of the boom is within the allowed amplitude angle range or scale length range of the boom section through comparison. The existing post-control is changed into pre-control. The safety of the device can be improved, and the risk of tipping can be reduced.