The invention relates to a preparation method of a toughness-improved melamine foam oil absorbing material. The preparation method comprises the following steps: pressing polypropylene or polyethylene into slices, cutting the slices into small blocks, putting the small blocks into methylbenzene or xylene, heating and refluxing at 110 DEG C, and dissolving to obtain a methylbenzene or xylene solution of the polypropylene or polyethylene; putting melamine foam into the solution, heating and refluxing at 110 DEG C for 15 to 60 minutes, taking out the melamine foam, removing the solution from the melamine foam, putting the melamine foam into a drying box and drying at 120 DEG C until constant weight to obtain the modified melamine foam. The preparation method has the beneficial effects that the melamine foam with high interior porosity serves as a matrix, so that the modified oil absorbing material has high oil retaining capability; the melamine foam does not need to be pretreated before modification; the toughness of the modified melamine foam is improved, the elongation at break is increased, the tensile capacity is improved, and recycling and reusing are facilitated; the foam modifying process is low in raw material cost and simple in process.