Abstract: In order to ensure the performance of the filter, reduce the volume of the filter and increase the number of chips on the wafer, a design method for the bulk acoustic wave (BAW) ladder filter is proposed. This method consists of 11 design rules and a design flow. The 11 design rules limit the shape and position of the BAW resonators (BAWRs), the distance between the BAWRs, the distance between the BAWRs and the pads and the interconnecting wire. There are 7 steps in the design flow: The first step is to preset the shape of each BAWR according to its active area value. The second step is to arrange BAWRs according to the BAW ladder filter circuit topology. The third step, "compression" layout. The fourth step, the BAWRs apodization, fine-tuning and rotation. The fifth step is to wire BAWRs and pads together. The sixth step is to detect if the layout of the filter meets the design rules. The seventh step, the use of a combined acoustic-electromagnetic BAW filter simulation method to verify the layout result. This paper presents the design rules and design flow of a 5-order BAW ladder filter with 10 series/parallel connected BAWRs. The optimized filter layout area utilization rate is 44%. Compared with the non-optimized filter layout, the optimized filter layout has lower insertion loss and higher out-of-band rejection. Thus we validate the feasibility of the layout design method.