Abstract: Alsalt composite was fabricated with pressure penetrating casting. Fabricating process of preform and the influence of process parameters on preform were studied. When binder content is about 10% and baking temperature is 720 and baking time is 5.4 ks, a preform with higher compressive strength can be obtained. With the help of SEM, the structure of the preform was observed before and after baking. By removing salt from the composite, porous Al can be obtained. Thermal expansion property also was studied. Comparison with compact aluminum, porous aluminum has a lower average linear expansion coefficient.