The invention discloses a slag salvage point optimization method and system and a slag salvage robot, and belongs to the technical field of slag salvage, and the method comprises the following steps:carrying out the first rectangular grid division based on a to-be-salvaged slag region, and forming n*m equant rectangular regions; carrying out slag-fishing sampling at a first intersection point formed by dividing the first rectangular grid in the to-be-fished slag region, and obtaining the weight of a sample subjected to slag-fishing sampling at the first intersection point; calculating an average value of the weights of the samples subjected to residue fishing and sampling at the first intersection point to obtain a first average value; judging whether the weight of the sample subjected toresidue fishing and sampling at each intersection point in the first intersection point is greater than the first mean value or not; if yes, obtaining a second intersection point; Taking the second intersection point as a slag fishing point; according to the method, full-coverage slag salvage or blind selection of slag salvage points is replaced, the method is simple and effective, the cost is low, and the slag salvage efficiency can be greatly improved.