In this paper we offered a new UI design for Chinese input method on smart devices during Gameplay. Currently the well-known conventional stroke-based Chinese input method using only five basic stroke types could achieve low leaning curve and small keypad implementation, we made the UI design base on this stroke-based input method compensating the problem that input speed is limited and finally relatively higher the input speed. For experiment we designed and implemented the new UI for input method by Unity3D. Input by pressing or typing keys is replaced by more using sliding. To improve the input speed of the stroke-based method slide direction arrows are used and selected character will be intuitively shown to user in real time as designed. And the Four Tones(四声) in Chinese pronunciation is also been used to improve the input speed for this input method. In addition, to evaluation the new input method UI, we have conducted experiments on smart device comparing with four basic Chinese input methods. Through the numeric values recorded in the evaluation by inputting random 20 Chinese characters and two-letter Chinese words, comparing the input speed, click times, the typo rate shows the advantages of the new UI and proved that the new UI is better than others for using in smart device game.