squirrel something away 
phrasal verb with squirrel verb uk/ˈskwɪr.əl/ us/ˈskwɝː.əl/
  informal      
 储藏,储存(尤指钱,供日后使用)
to hide or store something, especially money, in order to use it in the future
  As soon as I get paid, I squirrel some money away so I won't be tempted to spend it. 我一发薪水,就存起来一部分,以免忍不住想花。