The present invention provides a human Tim-3-Ig fusion protein which can block Tim-3 signal pathway, and said Ig fusion protein comprises Tim-3 protein, human Ig fragment, and the linking sequence therebetween. In the present invention, a human Tim-3-Ig gene is obtained by an artificial synthesis process; an expression vector containing the Tim-3-Ig gene is constructed; and the prepared Ig fusion protein is tested in an expression verification experiment, a binding activity experiment, a blocking activity experiment in different cell lines, and in vivo experiments in mice. The human Tim-3-Ig fusion protein prepared in the present invention can be used to treat immunological diseases caused by high expression of Tim-3.