Disclosed is a portable support frame for a musical instrument. The support frame comprises a supporting device I (1) for a handle portion of a musical instrument, and a supporting device II (2). The supporting device I (1) is movably connected to the supporting device II (2). The supporting device I (1) comprises an adjusting rod (3) with an adjustable length and a placing portion I (4) for placement of the handle portion of the musical instrument. The supporting device II (2) comprises an I-shaped supporting chassis (5), a movable adjusting frame (6) arranged above the supporting chassis (5), and a central connecting member (7). The adjusting rod (3) of the supporting device I (1) is arranged above the supporting device II (2) by means of the central connecting member (7) in an inserted manner, the bottom portion of the adjusting rod (3) extends out of the central connecting member (7), and a fixed rotary knob (8) is provided on a side face of the adjusting rod (3). The central connecting member (7) is hinged to an upper portion of the movable adjusting frame (6), placing portions II (9) for placement of the bottom portion of the musical instrument are respectively provided on two sides of the movable adjusting frame (6), and a movable clamp I (10) and a movable clamp II (11) are provided in the middle of the movable adjusting frame (6). The portable support frame uses a unique structural design, has a good supporting performance, and is convenient to fold, therefore saving on occupied space, being convenient to transport, being manufactured economically and rationally, and being suitable for popularization and application in society.