In the vertical operation areas of Leap Motion hardware, we use different heights of hands to manipulate the multilayer discrete target selection task mapped on the screen to get the number of layers suitable for user operation, and then analyze the corresponding human factors and make a discussion. Method: First of all, we can get user’s commonly used vertical operation scope through experiments, perform layered experiments on the basis of the common areas, and carry out linear analysis according to the time cost and index of difficulty (ID) in task, to prove its suitability of the Fitts' law model. Result: Through experiments we find that the linear fitting degrees(R2) of ID to task time under full visual feedback and partial visual feedback are 0.766 and 0.771, respectively, so the Fitts' law model is not suitable for multilayered discrete target selection tasks under layered interface. We also find that the maximum number of layers that can be operated by users under full visual feedback and partial visual feedback is 20 and 18 respectively through analysi on  time and error rate. Our conclusion can provide  technical design reference for application scenarios based on multilayer 3D interface.

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