Multifunctional denim warp dyeing machine

The invention provides a multifunctional denim warp dyeing machine, which comprises a to-be-dyed warp rack and a dyed warp reel. A warp pretreatment tank, a warp dyeing groove, a washing tank and a slashing tank are successively arranged between the to-be-dyed warp rack and the dyed warp reel, wherein the warp pretreatment tank is used for removing impurities of warps and washing the warps, the warp dyeing tank is used for dyeing the warps by indigo dyes or sulfur dyes, the washing tank is used for washing the dyed warps, a combined drying barrel, a small colorful dyeing tank and a steaming box are successively disposed between the warp pretreatment tank and the warp dyeing tank, the combined drying barrel is used for colorfully dyeing the warps, and the small colorful dyeing tank dyes the warps by reduced dyes. The problems that when warps are dyed, a color selection range is narrow, color fastness is poor, and the warps cannot be dyed by bright-colored dyes are resolved; after the dyed warps are woven into denim, the characteristics that the warps of the denim are colorful while wefts of the denim are white can be kept; composite dyeing by the aid of the indigo dyes or the sulfur dyes can be realized, and a dyeing effect is good.