The invention discloses a mobile phone bad use behavior risk early warning system based on a heart rate variability index, which comprises a module 1, a module 2, a module 3 and a module 4, the module 1, the module 2, the module 3 and the module 4 are connected in a wireless mode, the module 1 and the module 2 are connected through Bluetooth, the module 2 and the module 3 are connected through Bluetooth, and the module 2 and the module 4 are connected through WIFI. According to the mobile phone bad use behavior risk early warning system based on the heart rate variability index, possible physiology and emotion risks when a user uses a mobile phone can be monitored, the risk identification is based on the human body heart rate variability index and statistics, and considerable scientificity, exploratory performance and predictability are achieved; and according to the invention, the risk coefficients of users of different age groups using mobile phones in different body postures under different mobile phone using conditions can be evaluated.