In order to separate Sr²⁺ from the high irradiation waste, potassium tetratitanate whisker as ion-exchanger was synthesized by solid phase method. The ion exchange capacity for strontium was tested and their stabilities were studied. X-ray diffraction and electron microscopy (SEM) were used to study the crystal phases and the morphology. Exchanging and leaching amounts were tested by ICP-AES under different media and temperatures. The result indicated that the potassium tetratitanate fiber can be prepared by solid phase method,the exchanging rate is improved as the temperature increases, the maximal exchanging rate reaches to 93%, the immobility treatment is necessary,and the feasible immobile temperature is 500℃. The immobilized material is stable in the whole pH range.