The invention provides an adjustable sound barrier which comprises two stand columns, a base, a first sound insulation board, a second sound insulation board and an adjusting mechanism. The two standcolumns are arranged on the base, the first sound insulation board is arranged between the two stand columns and arranged at the bottom, one end of the first sound insulation board is fixedly connected to the left side stand column, and the other end of the first sound insulation board is fixedly connected to the right side stand column. The bottom of the first sound insulation board is fixedly connected to the base, and the two stand columns are provided with grooves. The two ends of the second sound insulation board are arranged in the grooves of the two stand columns respectively, and the height of the second sound insulation board can be adjusted up and down along the grooves. The adjustable sound barrier is simple in structure and reasonable in design, the second sound insulation board can be adjusted through the adjusting mechanism, the two ends of the second sound insulation board are clamped in the grooves of the two stand columns, and the height of the second sound insulationboard can be adjusted up and down along the grooves, so that the height adjustment of the whole sound barrier is achieved; and a sound absorption device at the top of the second sound insulation boardcan greatly improve the noise reduction effect when the second sound insulation board is in the low position.