<p>The feeble wear resistance of H13 steel processed by laser powder bed fusion (LPBF) significantly affect its service life. In this work, the densification behaviour, microstructural evolution and wear resistance of LPBF processed WC-Co reinforced H13 steels is investigated with focus on the effect of WC-Co content. The results reveal that the microstructure of H13 changes from cellular structure to columnar coexistence structure with the addition of WC-Co. Meanwhile, the addition of WC-Co refines the grains and induces massive dislocations in the H13 matrix. Due to the in-situ reaction between WC-Co particles and H13 steel, a (W, M)C₂ (M = Co, Cr, Mn, V) gradient interface layer is formed between WC-Co and H13, which effectively enhances the interface bonding and ameliorates the density of the sample. With increasing WC-Co content, the interface layer become finer and more uniform while exhibiting a corresponding increase in Vickers hardness. When the content of WC-Co is 3%, the Vickers hardness reaches the maximum of 846.8 HV. Wear test reveal that 3%WC-Co/H13 exhibited the lowest values of friction coefficient (0.59) and wear rate (0.77 × 10^− 7 mm³/Nm). This is attributed to the (W, M)C₂ interface layer can act as a buffer to slow down the wear of the grinding ball on the sample. Besides, the high hardness WC-Co particles play a role of pinning the skeleton, which enhances the strength of the friction surface, improves the wear resistance of the composite sample. Moreover, the underlying wear mechanisms of printed samples are compared and discussed.</p> Graphic Abstract <p></p>