All perfect praise be to Allaah, the Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is permissible for a person to pray on a bed used for sleeping even if he does not put a prayer mat on it if the place of the prayer is pure and the praying person is able to fulfill all the conditions and pillars of the prayer properly without causing any deficiency in the prayer. Shaykh Al-Fawzaan said: “It is permissible for a person to perform prayer on something high, like a bed and the like, if it is pure and stable, and not moving or causing any deficiency or disturbance for the praying person.”
For more benefit, please refer Fatwa 92146.
Allaah Knows best.