The Shenzhen Metro network currently consists of five lines and 137 stations stretching across the entire city.

Fares range in price from RMB2 to RMB11, based on the distance traveled. Seniors’ and childrens’ discounts are available.

The best way to travel on the metro is by purchasing a Shenzhen Tong, or cash card, which can be swiped at the ticket gates to board the train. Adding value on Shenzhen Tong cards can be done at any of the Shenzhen Metro stations. If you are planning only a single journey, you may purchase single fare tokens at the station kiosks or through automatic ticketing machines.

Below is a map of the Shenzhen Metro network. Clicking on the map will enlarge it for easier viewing.

(Click to enlarge)

You can find more details on the Shenzhen Metro network here:
Shenzhen Metro official website
Wikipedia