A package structure for optical module includes a substrate, a cover, a light emitting chip, a light receiving chip and two package colloids. The substrate has a recessed portion. The cover is installed on the substrate and a first chamber and a second chamber are formed between the cover and the substrate. The cover has a light emitting hole connected to the first chamber, a light receiving hole connected to the second chamber, and a blocking wall installed in the recessed portion for separating the first chamber and the second chamber. The light emitting chip and the light receiving chip are installed on the substrate and housed in the first and the second chambers, respectively. The two package colloids are respectively installed in the first and the second chambers and wrap the light emitting chip and the light receiving chip, respectively. In this way, the package structure for optical module can not only prevent crosstalk but greatly reduce manufacturing cost and lower manufacturing difficulty.