The chemical fertilizers are abused to improve crop yields, which cause lots of soil problems (e.g., soil compaction and native nutrient loss). We thus investigated the potential of the combination of biochar and wood vinegar as a new type of fertilizer to replace the traditional fertilizer. The results in this study showed that the combined addition of biochar with wood vinegar had the greatest promotion effect on the plant growth of cucumber. Compared to the control treatment, the biochar addition with wood vinegar significantly increased the plant height, root length, root volume and root tips by 29.7%, 117%, 121% and 76.1%, respectively. These positive effects could be attributed to the benefits of the addition of biochar with wood vinegar treatment on improving soil fertility, increasing nutrient supply, and further stimulating plant growth. Overall, the combination of biochar and wood vinegar could be a promising fertilizer to promote plants growth and enhance crop yields.