The invention discloses a portable stone crusher. The portable stone crusher comprises a material barrel and a rack, wherein the material barrel is fixed to the rack; a crushing shaft consisting of a rod cap and a rotating shaft body is arranged in the material barrel; a limiting part is formed between the rod cap and the rotating shaft body; a first crushing assembly and a second crushing assembly are arranged on the limiting part; the first crushing assembly comprises a first connecting rod, a first crushing rod and a first crushing blade; the first connecting rod and the first crushing rod are connected through a bolt; the first crushing rod and the first crushing blade are connected through the bolt; the second crushing assembly comprises a second connecting rod, a second crushing rod and a second crushing blade; the second connecting rod is connected with the second crushing rod through the bolt; the second crushing rod is connected with the second crushing blade by the bolt; a connecting flange is arranged between one end of the rotating shaft body and a motor. With the adoption of the portable stone crusher, the crushing range is changed; the concrete flowability is improved; the crushing time can be reduced; the concrete can be prevented from being deposited to the bottom part of the material barrel; meanwhile, a crushing device can be conveniently replaced, and the construction cost can be reduced.