The invention provides an indoor positioning navigation method and system for visually impaired people. A user terminal executes the following steps: receiving of environment data: the environment data collected by an environment detecting unit is received; sending of a two-dimensional layout map request: the request for giving the two-dimensional layout map of a building is sent to a server; positioning: a current position of a user is calculated based on the two-dimensional layout map in combination with movement data of the user; navigation: an optimal route is calculated with a route planning algorithm in combination with the current position and the destination of the user, voice navigation is performed for the user, and during voice navigation, when the environment detecting unit detects an obstacle, obstacle data information sent by the environment detecting unit is received, and voice prompts the user to bypass the obstacle. The indoor positioning navigation method and system have the beneficial effects of being suitable for all kinds of user groups, particularly have a quite good assisting effect on the visually impaired population, and is worth applying and popularizing.