The causes of the Iflytek electromagnetic pen eraser jitter are: insufficient battery power, too far distance between the electromagnetic pen and the computer, and electromagnetic interference.

1, insufficient battery power: the battery power of the electromagnetic pen is insufficient, which will cause the eraser of the electromagnetic pen to shake.

2. The distance between the electromagnetic pen and the computer is too far: the electromagnetic pen is too far away from the computer, and the signal is unstable, which will cause the eraser of the electromagnetic pen to shake.

3. Electromagnetic interference: There are other electronic devices or electromagnetic interference sources around, which will cause the electromagnetic pen to shake.