Wireless sensor networks（WSNs） is a kind of energy-constrained networks.Any search algorithm based on wireless sensor networks must be taken into account the issue of how to save energy.Because of the characteristics of many parameters and small change in parameters

a predicate-based query optimization algorithms（PQOA-WSNs）has been designed.Starting from the user’s predicate query expression

the query type is converted to equivalent disjunctive paradigm

and then query optimization algorithm makes the best sort order in order to reduce the amount of data and extend the sensor network lifetime according to studies based on the principle of probability.In this paper

PQOA-WSNs algorithm includes the lexical and grammatical analysis

the conversion formulas and the probability of algorithm modules.Simulation tests show that the more sampling parameters

that is

the more sampling predicate

the more obvious optimization algorithm is.In case of 2

3

4

5

7 predicates in the query conditions

optimize the rate of the test were 48 %

65 %

74 %

78 % and 85 %.