A general-purpose parallel three-list six-table algorithm that can solve a number of knapsack-like NP-complete problems is developed in this paper. This kind of problems includes knapsack problem, exact satisfiability problem, set covering problem, etc. Running on an EREW PRAM model, The proposed parallel algorithm can find a solution of these problems of size n in O(2^7n/16) time, with O(2^13n/48) space and O(2^n/8) processors, resulting in a time-space-processor tradeoff of O(2^5n/6). The performance analysis and comparisons show that it is both work and space efficient, and thus is an improved result over the past researches. Since it can break greater variables knapsack-based cryptosystems and watermark, the new algorithm has some cryptanalytic significance.