What reason is calluses on the soles of feet, and it still hurts?

It doesn't have to be calluses. Calluses generally don't cause pain, so consider whether it is corns. Cornus is a physical skin disease, which is caused by friction and hyperkeratosis to form a hard nucleus to stimulate the skin and cause pain. As long as the friction coefficient is still there, it will get bigger and bigger. So first of all, we should eliminate the friction factor, wear loose shoes, and then carry out exfoliation treatment, such as using salicylic acid phenol plaster. You can also choose cryotherapy and laser therapy.