The invention discloses a wide lane ambiguity resolution method through BDS and GPS observation information fusion. The method comprises the steps of firstly, using the triple-frequency advantage of a BDS and performing preferred and reliable single-epoch fixing of the combination ambiguity of a ultra wide lane and a wide lane of the BDS; and secondly, using short-term stable variation characteristics of ionized layer delay, parameterizing inclining ionized layer delay values of different satellites of the BDS and the GPS, and using the ionized layer frequency relationship for simultaneously solving different combination observation values (including a pseudo-range), wherein, the BDS comprises pseudo-range observation values at three frequency points and ultra wide lane or wide lane observation values with two fixed ambiguities and the GPS comprises pseudo-range observation values at two frequency points and wide lane observation values with the wide lane ambiguity to be evaluated. Common position increment parameters are used for fusion of the above observation information, and a geometric correlation model is made for kalman filtering. The method provided by the invention can be used for significantly increasing the resolution precision and speed of the wide lane ambiguity of a dual-frequency system, especially of a low altitude angle satellite.