In order to improve the inkjet printing performance of linen fabric, sodium dodecylsulfate (SDS) and sodium alginate (SA) were synergistically used in the pretreatment process of linen fabrics. The spreading area of ink droplets on the fabric surface and the color parameters of inkjet printing color block were tested. Using contact angle measuring instrument, scanning electron microscope (SEM), solid surface zeta potential, X-ray photoelectron spectrometer (XPS) and Fourier transform infrared spectrometer (FTIR) to analyze the surface physical and chemical properties of linen fabric before and after pretreated. The results show that the degree of ink drop penetration on the surface of the fabric was significantly reduced when the SDS added, and the spreading area of magenta ink drops was decreased by 14%, compared with SA pretreated. The color effect of cyan and black blocks was slightly increased. The rubbing fastness of the printed fabric slightly reduced, the breaking strength and sunlight fastness has not affected. After pretreated, it can be clearly seen from the SEM image that the SDS+SA pretreatment agent formed a film on the surface of the fabric, and the serrated membrane structure between the fibers blocks the pores, prompting more reactive dyes covalently bond with fibers at the dropping position, in addition, the hydrophilicity of the fabric after pretreatment treatment was increased, which is beneficial to the dye uptake of linen fibers.