The explosion characteristics and influential factors of suspended calcium carbide (CaC2) dust were studied using a 20-L spherical vessel. Acetylene (C2H2) and calcium hydroxide (Ca(OH)(2)) are the reaction products of CaC2 and water. Therefore, C2H2/Ca(OH)(2) mixture was used as the reference sample in the experiment. Experimental results showed that the water content in the environment (air relative humidity and external water drops) had significant impacts on CaC2 dust explosion. The explosibility of CaC2 dust enhanced with the increasing air relative humidity In the experiments, CaC2 dust and dry water were equally proportioned when the value of stoichiometric ratio R was 1. When the concentration of hybrid CaC2/dry water increased, the value of P-ex of CaC2/dry water explosion rose first and then stabilized at 0.74 MPa, and the value of (dP/dt)(ex) showed a trend of rising first and then declining after reaching the maximum value of 238.25 MPa s(-1) P-ex and (dP/dt)(ex) of pure C2H2 explosion and C2H2/Ca(OH)(2) hybrid explosion increased at the early stage and then decreased for the increasing C2H2 content. P-ex and (dP/dt)(ex) of the three samples increased in the following order: hybrid CaC2/dry water < hybrid C2H2/Ca(OH)(2) < pure C2H2. Dry CaC2 dust did not explode, but its explosibility was significantly enhanced for the increasing water content in the environment, and the main reason was the existence of C2H2. (C) 2019 Elsevier B.V. All rights reserved.