Abstract: Aiming at the requirements of wide frequency band, low power consumption and easy operation for the calibration of vector network analyzer（VNA） and its test connection system, an adjustable micro-electro-mechanical system（MEMS） SOLT calibration part for L～Ka band was designed. The structural calibration component was based on series and parallel MEMS switches. First, a series-parallel hybrid MEMS switch was designed, and the load resistance was integrated with the MEMS switch. Combined with the SOLT principle of the calibration component, the switch was used to select the signal. The pass-through function can realize four calibration states of short-circuit, open-circuit, load and pass-through. The calibration piece of the structure makes up for the shortcomings of the traditional calibration piece with complicated operation and large human error, and has the characteristics of small size, high precision and easy operation. Using HFSS simulation software to optimize the performance of the device, in the L～Ka band range, the loss of the device in the straight-through, open-circuit and short-circuit states is better than 1.89 dB, 1.8 dB and 0.33 dB, respectively, and the impedance is stable at 50.5 Ω.