In this work, starting from a Painlev-Bcklund transformation and a multil inear variable separation approach, a general variable separation excitation of the three-dimensional Boiti-Leon-Pempinelli system is derived first. Then based on the derived excitation, we can construct many localized structures like pe akons and compactons etc. Meanwhile, two new types of solitary waves, i.e., a b ell-like loop soliton and a peak-like loop soliton are constructed and their e volution properties of the novel localized structures are briefly discussed.