The shortages of algorithms for getting controllable canonical forms of the multi-input system in current references are analyzed. New modified algorithms for getting controllable canonical forms of the multiinput system have been put forward. By using the elementary row transformation in the controllable matrix, the input matrix is replaced by the maximally linear independent set of its column vectors. These algorithms can also perform the canonical forms in the systems are not controllable. It is a clear ways of thinking, less computing work and feasible to realize in computer.