The present invention discloses a portable waist drum capable of shoulder strap adjustment and assistant fixing. The portable waist drum comprises a drum body, a shoulder strap, a shoulder strap length regulation device, an assistant position fixing device and a colored lamp device. The shoulder strap length regulation device is formed by a fixing base, a T-shaped fixing rod and line-shaped limiting holes; the assistant position fixing device is formed by rectangular ports, fixed racks, fixed circular shafts, rolls, torsional springs, assistant position regulation devices, waist straps, insertion buckles and sub buckles; each assistant position regulation device is formed by a rectangular long slot, a fixed block, a slide block, a rectangular straight slot, a block pulley, rectangular grooves, movable pressing plates, reset springs, locating pins and locating holes; and the colored lamp device is formed by a circular straight slot, colored lamps, transparent ring covers, a battery jarand a power button. The portable waist drum capable of shoulder strap adjustment and assistant fixing is simple in structure and high in practicality.