The Nd3+ ion doped in Nd∶YVO4 crystal has a weak laser transition at 1.342 μm in addition to 1.064 μm stimulated transition. The laser at 1.342 μm can be frequencydoubled to obtain red light at 671 nm. In this paper, the analysis and the experiment of a Nd∶YVO4 crystal pumped by 400μm fibercoupled diode array, typeⅠ critical phase matching and intracavity frequencydoubled LBO (LiB3O5) crystal, and red laser at output wavelength of 671 nm were performed. By using a short foldedcavity resonator, the thermal focal length of Nd∶YVO4 crystal was calculated, and the parameters of laser cavity were selected by computer optimum design. At last, with incident pump power of 8 W, TEM00 mode (transverse electromagnetic mode) red laser at 671 nm of 1.8 W was obtained, with the optical conversion efficiency up to 22.5%.