The invention provides a method and device for obtaining the swing angle of a lifting appliance and an anti-swing method and device for a crane, and relates to the anti-swing field of lifting equipment. According to the method for obtaining the swing angle of the lifting appliance, track deflection change is considered when the actual swing angle of the lifting appliance is calculated, after the deflection angle of a trolley platform in the vertical direction and the to-be-optimized swing angle of the lifting appliance in the moving direction of the trolley platform are obtained, the actual swing angle of the lifting appliance is calculated according to the two parameters, and therefore the effect that the calculated actual swing angle is accurate can be guaranteed to a certain extent, and anti-swing control with the calculated actual swing angle is made more efficient.