The invention relates to a fluffy granular composite low-sugar and low-calorie table sweetener and a preparation method. The sweetener comprises the following components: 60-75% of dextrose monohydrate, 10-15% of erythritol, 10-25% of sorbitol, 3-5% of maltodextrin and 0.8-1.70% of sucralose. The process comprises the following steps: respectively adding the maltodextrin and the sucralose to a heating container and respectively adding deionized water for mixing; raising the temperature until dissolution; adding activated carbon to the solution respectively, filtering the mixture while the mixture is hot and collecting the filtrates respectively in storage tanks; and pumping the ground mixture of the dextrose monohydrate, the erythritol and the sorbitol into a fluidized bed with spraying from the bottom of the bed under positive pressure and ensuring the mixture to flow at high speed from bottom to top, applying negative pressure to the upper part of the fluidized bed with spraying so that the bed vibrates from top to bottom to ensure the materials to boil in the bed; using a multipoint spray gun at the side of the fluidized bed to continuously spray and disperse the refined sucralose solution on superfine sugar alcohols, then pumping the maltodextrin solution and carrying out continuous spray drying, thus obtaining the low-sugar and low-calorie table sweetener. The sweetness of the product is 5-10 times that of the common sucrose.