A sound-insulating pipe clamp, with a pipe pre-fixing system, comprising two main coupling components (1, 2), a locking mechanism for the two main coupling components and a connecting mechanism for fixing the clamp to a support; wherein after the pipe is clamped by the two main coupling components and locked by the mechanism, a circular shape, or an approximate circular shape, is formed; to this end, the arc length of the first main coupling component of the two main coupling components is greater than a semicircular arc, and that of the second main coupling component is smaller than a semicircular arc; wherein this sound-insulating pipe clamp is characterized in that: a) the sound-insulating cushion pads (4, 5) are adhering to the inner surfaces of the two main coupling components (1, 2), of which the first main coupling component has an arc length that is greater than a semicircular arc, and the lenght of the inner arc surface of the first main coupling component to which the sound-insulating cushion pad is adhering is smaller than or at most equal to a semicircular arc; b) the right and left inner sides of the arc surface where the inner surface is greater than or equal to the semicircular arc of the first main coupling component, which has an arc length that is greater than a semicircular arc, are equipped with hard cleats (6, 7). c) the smallest distance between the left and right hard cleats (6, 7) is a little less than the inner diameter of the inner circular arc to which cushion pad is adhering. d) each cleat has a pair of wings that are located at both ends of the cleat and thus form the "∩" shape, wherein the two wings form the symmetrical left and right parts of the "∩" shape respectively, and the inner distance between the two opposite wings is a little larger than or equal to the width of the cushion pad; both ends of the cushion pad are clamped within the "∩" shape wings of cleats (6, 7) respectively, so that the cushion pad is protected and to avoid moving and falling off. a) the sound-insulating cushion pads (4, 5) are adhering to the inner surfaces of the two main coupling components (1, 2), of which the first main coupling component has an arc length that is greater than a semicircular arc, and the lenght of the inner arc surface of the first main coupling component to which the sound-insulating cushion pad is adhering is smaller than or at most equal to a semicircular arc; b) the right and left inner sides of the arc surface where the inner surface is greater than or equal to the semicircular arc of the first main coupling component, which has an arc length that is greater than a semicircular arc, are equipped with hard cleats (6, 7). c) the smallest distance between the left and right hard cleats (6, 7) is a little less than the inner diameter of the inner circular arc to which cushion pad is adhering. d) each cleat has a pair of wings that are located at both ends of the cleat and thus form the "∩" shape, wherein the two wings form the symmetrical left and right parts of the "∩" shape respectively, and the inner distance between the two opposite wings is a little larger than or equal to the width of the cushion pad; both ends of the cushion pad are clamped within the "∩" shape wings of cleats (6, 7) respectively, so that the cushion pad is protected and to avoid moving and falling off.