It is urgent to design efficient photocatalysts for wastewater treatment due to the increasing severity of water pollution and the superiority of photocatalytic technology. In this work, a novel BiOI–BiOCl/NFs composite photocatalyst was prepared via electrospinning and one-pot solvothermal method. The BiOI–BiOCl nanosheets with cross-flake arrays were evenly grown on the PAN fiber. The as-prepared ICl-31 sample could degrade 98.7% RhB within 60 min and 82.1% TC within 120 min visible-light irradiation, the RhB degradation efficiency was 7.61 and 4.19 times than that of individual BiOCl and BiOI samples respectively, and the TC degradation efficiency was 2.7 and 1.89 times than that of corresponding samples, respectively. Meanwhile the prepared samples have great cycle stability. The improvement of photocatalytic performance should be ascribed to the organic combine of PAN nanofibers carrier and the construction of BiOI–BiOCl heterojunction. The direct Z-scheme migration mechanism was proved by trapping experiments. An internal electric field will be formed when the interface of BiOI and BiOCl are in contact. The internal electric field will expedite the transfer rate and separation efficiency of photogenerated carriers, therefore the photocatalytic efficiency was improved significantly. A series of BiOI–BiOCl/NFs were prepared via electrospinning and one-pot solvothermal method. The nanosheets with cross-flake arrays were uniformly grown on the surface of PAN fibers. The direct Z-scheme heterojunction was constructed, hence the photogenerated carriers with highly separate efficiency. Most importantly, the prepared BiOI–BiOCl/NFs composite catalysts showed great photodegradation capability of RhB and TC. • Visible-light-driven BiOI–BiOCl/NFs was prepared by electrospinning and one-pot solvothermal method. • The prepared composite photocatalyst with great cyclic stability. • The direct Z-scheme heterojunction was constructed. • Highly enhanced photocatalytic degradation of RhB and TC was observed.