[Objective] The soil water evaporation characteristics of soil cracks after different backfilling techniques was analyzed in order to provide scientific basis for the effective control of soil cracks in the dump hence promote ecological environment restoration and land reclamation. [Methods] The soil was collected from the surface of the west dump of Haizhou open-pit mine and the soil cracks were simulated by backfilling treatment and analyzed by the simulated evaporation test in the laboratory. [Results] The daily evaporation of cracks showed an obvious three-stage evaporation rule, and different backfilling treatments had little effect on the daily evaporation of cracks. With the increase of crack width, the cumulative evaporation of cracks increased and backfill treatment effectively reduced the cumulative evaporation of cracks. The cumulative evaporation of cracks with a backfilling ratio of 1∶1 (treatment 1) was the minimum value under the same group of cracks backfilling. The appearance of cracks would lead to the reduction of soil moisture content, but backfill treatment could improve the moisture content of cracks, and the water content of backfilling ratio of 1∶1 (treatment 1) was the highest value of the three groups of cracks, with an average value of 29.74%. The increase of crack width also had an impact on the evaporative water-loss ratio and the backfill treatment could reduce the evaporative water-loss ratio. The backfill ratio of 1∶1 (treatment 1) had the best performance in reducing the evaporative water-loss ratio. [Conclusion] The existence of cracks has an effect on the daily evaporation, cumulative evaporation, water content, and evaporation water loss ratio of cracks, and the 1∶1 backfill ratio (treatment 1) has the best performance in the study of water evaporation of soil cracks in the dump.