The effect of Rh3+ catalyst on the combustion of the Crude Vegetable Oil droplet, namely coconut, jatropha, and sunflower oil has been studied experimentally at atmospheric pressure and room temperature. The oil droplets contain multi-component elements that are saturated fatty acid, monounsaturated fatty acid, polyunsaturated fatty acid, and glycerol. Results demonstrated that the catalyst has a stronger influence on crude coconut oil (CCO) and crude sunflower seed oil (CSFO) polar compounds during combustion, indicated by a greater enlargement of their triglyceride chains relative to those in crude jatropha oil (CJO). The changes in triglyceride geometry were identified as the cause of the distinguishing CVO droplet combustion characteristics. During the heating process preceding ignition, internal evaporation occurs with the appearance of bubbles trapped in oil droplets, and it appears that the diameter of the CJO droplet is greater than that of CCO and CSFO. This result suggests that the non-polar CJO compounds are more saturated, requiring additional heat for evaporation and ignition. The results also show that the catalyst makes multi-step burning droplets becomes shorter in one stage with the highest burning temperature. This proves that the catalyst does not only enlarge the triglyceride geometry but also excites the electrons due to hydrogen atom attraction as well.