MnZn ferrite thin films are deposited by alternative sputtering technique from two targets with the composition of MnFe2O4 and ZnFe2O4, and the behavior of the magnetic properties of the MnZn ferrite thin films irradiated by Kr26+ ions at energy of 2.03 GeV is investigated by magnetization measurements. The fabricating and modifying conditions on the performance of the films are studied to improve Ms and reduce Hc of the films, making the films suitable to the applications of high-frequency film devices. For Mn1-xZnxFe2O4 thin films, the Ms increases firstly then decreases and Hc decreases monotonously with increasing Zn content. And both Ms and Hc are sensitive to Kr26+ ion irradiation and exhibit different behaviors depending on the ion fluence range. The modifications of the magnetic properties could be interpreted very well by the effects related to the stress and defects induced by SHI irradiation.