A step high adjusting type modulization combined staircase comprises a staircase beam which is a slant combined beam formed by connecting plural beam blocks by connecting rods, each beam block is provided with an upper adjusting hole and a lower adjusting hole, a round hole is arranged between the upper adjusting hole and the lower adjusting hole, each connecting rod penetrates the upper adjusting hole, the round hole and the lower adjusting hole sequentially to connect three beam blocks, at least a left pedal and a right pedal are arranged at two sides of the staircase beam, the step high and step length of the left pedal and the right pedal are mutually staggered, the initial step and the tail step of the pedal are respectively arranged at two ends of the staircase beam; the left pedal and the right pedal are opening box bodies with one end provided with a convex block. For the step high adjusting type modulization combined staircase provided in the invention, each part can be demounted and remounted and is suitable for industrial mass production, having better assembly and movability; the invention can adjust step high according to the height between floors within the hole diameter of the upper adjusting hole or the lower adjusting hole, having strong environment adaptability and functions of decoration and stuff storage.