In a voice-controlled navigation device and method, a voice command is received, and divided into voice segments Vi (i=1˜n) by comparing with one or more keywords. A voice segment Vi (i=1˜n) is obtained in sequence to be compared with tree nodes in a search tree of place names. A weight value of each tree node is computed according to a comparison, to select one or more tree nodes whose weight values are greater than a predetermined value. Routes formed by all the selected tree nodes are obtained to select a route whose total weight value is the greatest. A navigation to a destination is given by indicating the selected route on an electronic map according to place names represented by the tree nodes of the selected route.