A built-in air pump for an inflatable body, comprising: a housing body and a panel , said panel being coupled to said housing body and defining an opening in fluid communication with an outer environment of the inflatable body; a main pump body coupled to said housing body and defining a first accommodating chamber , a first venting port , and a second venting port , said first accommodating chamber being in fluid communication with said opening , said first venting port and said second venting port ; a main pump , located inside the first accommodating chamber ; an air replenishing pump having an air replenishing pump body , said air replenishing pump body located adjacent to said main pump body , said air replenishing pump body defining a second accommodating chamber having therein said air replenishing pump ; a first connecting member , located between said main pump body and said housing body to connect said main pump body to said housing body ; a second connecting member , located between said air replenishing pump body and said housing body to connect said air replenishing pump body to said housing body ; an air passage switch located in said first accommodating chamber , said air passage switch being moveable between a first position and a second position; wherein when said air passage switch is in said first position, said air passage switch , said main pump body , and said first venting port collectively define an inflation air passage; wherein when said air passage switch is in said second position, said air passage switch , said main pump body , and said second venting port collectively define a deflation air passage; and a controller in electrical connection with said air replenishing pump , said controller configured to activate said air replenishing pump based on a time determination. a housing body and a panel , said panel being coupled to said housing body and defining an opening in fluid communication with an outer environment of the inflatable body; a main pump body coupled to said housing body and defining a first accommodating chamber , a first venting port , and a second venting port , said first accommodating chamber being in fluid communication with said opening , said first venting port and said second venting port ; a main pump , located inside the first accommodating chamber ; an air replenishing pump having an air replenishing pump body , said air replenishing pump body located adjacent to said main pump body , said air replenishing pump body defining a second accommodating chamber having therein said air replenishing pump ; a first connecting member , located between said main pump body and said housing body to connect said main pump body to said housing body ; a second connecting member , located between said air replenishing pump body and said housing body to connect said air replenishing pump body to said housing body ; an air passage switch located in said first accommodating chamber , said air passage switch being moveable between a first position and a second position; wherein when said air passage switch is in said first position, said air passage switch , said main pump body , and said first venting port collectively define an inflation air passage; wherein when said air passage switch is in said second position, said air passage switch , said main pump body , and said second venting port collectively define a deflation air passage; and wherein when said air passage switch is in said first position, said air passage switch , said main pump body , and said first venting port collectively define an inflation air passage; wherein when said air passage switch is in said second position, said air passage switch , said main pump body , and said second venting port collectively define a deflation air passage; and a controller in electrical connection with said air replenishing pump , said controller configured to activate said air replenishing pump based on a time determination. <EOS>