A fish-like underwater robot includes a shell, a driving assembly and an integrated tension and swing component. The integrated tension and swing component includes a plurality of tension ropes and tension elements. Every two adjacent tension elements are connected in series through the plurality of tension ropes. The driving assembly and the integrated tension and swing component are disposed inside the shell. The driving assembly is disposed at a head of the shell. The integrated tension and swing component has an end connected to a tail of the shell and an end connected to the driving assembly. When the fish-like underwater robot is used, the driving assembly drives the integrated tension and swing component to swing to generate power for forward movement. A traditional fish-like tail swing structure is replaced with an integrated tension skeleton structure.