For the stability of scaffold commonly used in civil engineering, the continuous compressing bar calculation method with multi elastic supports and multi nodes is adopted with the weight of the bar considered based on a variety of traditional method. It is applied in the scaffold design and calculations of Yuping Yihe Bridge of Shandong Linyi. The calculating results show that, in general, the impact of the weight of the scaffold itself on the critical load can be ignored. But when the scaffold weight is large, the critical load has decreasing decent. The scaffold design proposed based on this method proved reasonable and reliable and ensured the smooth progress of the construction.