Abstract: Micro-pattern gas detectors (MPGDs) have been applied in many fields. With the rapid development of MPGDs, readout electronics system has been a bottleneck to the further application of MPGDs. This paper presents a FELIX-based scalable readout electronics system facing the problem. It consists of pre-amplifier modules, a FELIX which acts as a data router between front-end electronics and DAQ system, 2 GBT (gigabit transceiver) modules based on FPGA which acts as a bridge between chip carrier and FELIX, and chip carriers whose main function is detector signal conditioning and digitization. The prototype system has 10 240 electronic channels applying semi-digital ASIC MICROROC and 4 096 electronic channels applying analogue ASIC AGET. Results of joint tests with Micromegas indicate the system works well with different kinds of chip carriers. The design offers a flexible readout solution for different application scenarios of MPGDs.