The present invention teaches a sitting and sleeping furniture with arbitrarily adjustable inclination, comprising: a back (10), a sitting and sleeping platform (13), a plurality of back columns (2), a back column cross frame (5), and a plurality of sitting and sleeping platform frames (14), the back columns (2) is connected with the back column cross frame (5) to form back column framework, the sitting and sleeping platform frames (14) are connected with the back framework to form a sitting and sleeping platform skeleton, wherein a parallel mechanism is set at the position below the bottom of the back and above the sitting and sleeping platform (13) containing a lead screw or roundabout pulling rope (31), and a hydraulic or pneumatic cylinder or a worm controller serving to control the supporting arm; and a synchronous lifting mechanism serving to cooperate with the parallel mechanism to keep the top of the back be parallel with the bottom of the back is set on the upper side of the back (10).