abstract: Self-interacting dark matter (SIDM) is a favorable model which can solve problems existing in standard collisionless cold dark matter (CDM). Sommerfeld enhancement and formation of bound state due to the mass hierarchy between the DM and the mediator become non-negligible in SIDM model, as the result, DM annihilation rate and relic density can be altered from simple ones. Besides, if the mediator decouples from Standard Model in order to escape from direct detection constraints, hidden sector temperature temperature evolves differently from visible sector, and it also affects the observables of DM. We study above phenomenologies in next-to-minimal supersymmetric standard model (NMSSM) as the benchmark model.