An integrated device was designed which was composed of thermo-optic switch and delay line array. Rsoft software was used to optimize the parameters of digital multi-mode interference thermo-optic switch, and the varied output signal intensity can be achieved with changing the temperature of an electrode. Then a delay line with a helical structure was designed. Spiral waveguide structure was simulated by BPM software. Considering the size of the device and the loss parameter, a reasonable bend radius of the spiral structure was designed. The integrated delay line array structure with the thermo-optic switch has a maximum delay time of 399.4 ps and the corresponding delay interval is 9.2 ps. The device has three layers, which are fabricated by using SiO2 as lower cladding layer, SU-8 photoresist as core layer and polymethylmethacrylate as upper cladding layer. By spin coating, lithography and wet etching, an integrated device with 1×4 MMI thermo-optic switch and delay line array was fabricated, and near-infrared field patterns of the delay line array was tested with insertion loss of 15~19 dB.