Reliability Analysis is applied into tower structural design and influence of uncertain factors is considered into the design. The reliability robust optimization mathematical model of tower structure is established by combining the reliability optimization designing theory with the robust design method and injecting reliability sensitivity into the design model. The reliability sensitivity is added to the reliability-based optimization design model and the stiffness reliability-based robust design is reduced to a multi-objection optimization. Take the lattice tower structure for example, after designing, it shows not only lighter weigh, saving in material, simplifying construction, but also improving its safety and stability. The example proves the method to be effective.