This invention relates to a kind of preparation method of E-cigarette liquid. The process is as follows. First, put the tobacco with the amount of 5-20% of E-cigarette liquid volume into the extracting tank and add the mixed solvent into the tank to soak the tobacco for 30-100 minutes. Then, heat the mixture up to 40-60°C and extract with warm soak for 2-8 hours. Filter the extract and add chocolate extractive with the amount of 1-10% of the E-cigarette liquid volume into the filtrate and stir it for 20-40 minutes. Then use propylene glycol or polyethylene glycol to complement the E-cigarette liquid volume with 100% planning preparation and stir uniformly to get the product. Letting the natural aroma elements of tobacco enter the E-cigarette liquid, this method makes the aroma and taste come from the tobacco and be closer to those of cigarettes, which can cater to the smoking feeling of customers and makes the time much longer for keeping the natural aroma in cigarette liquid.