When dyes were used for inkjet printing on multi-component fabrics, the complex acid-base conditions, high temperature and high humidity posed a challenge to the stability of water-soluble polymers covered the surface of the fabrics. In this study, hydroxypropyl methyl cellulose (HPMC) was used to construct a continuous film on the surface of cotton/polyamide interwoven fabric. The results show that the formation of ridges between fibers is closely related to the properties of HPMC. Fibers in the yarn were connected to each other by HPMC, which prevented inks from penetrating into the bottom of the yarns. Meanwhile, HPMC maintained high viscosity under acidic conditions, which provided conditions for reactive dyes to dye polyamide fibers under acidic conditions. Compare with sodium alginate, the color depth of cyan, magenta, yellow and black improved by 75.1 %, 101.8 %, 181.3 %, 207.5 % on cotton/polyamide fabrics using HPMC, separately. Hydroxypropyl methyl cellulose is effective to improve inkjet printing for cotton and polyamide fiber, which has the possibility of widespread application in natural fiber and synthetic fiber. • Hydroxypropyl methyl cellulose membrane is constructed to connect adjacent fibers. • The formation of ridge structure is due to the high viscosity of HPMC solution. • The ink penetration is constrained along the direction perpendicular to the fabric. • The inkjet printing effect of C/PA fabric is improved with the help of HPMC film.