What should I eat when you have kidney stone?

Low salt &drink lots. Reduce salt intake, reduce or limit animal protein intake. Reduce other protein (eggs, fish meat) & oxalate containing foods (nuts, spinach, rhubarb wheat bran) if calcium oxalate stones. Most important is to drink lots of water, aim for 10 glasses/day. Get enough calcium (milk & chhese is ok) they do not, and salt does, contribute to forming calcium stones.