Geopolymer is a material synthesized from a base material with a large amount of silica and alumina. Geopolymer can be used as an affordable alternative as a substitute for Portland cement, reducing pollution, and resistant to fire under certain conditions. But pure geopolymer has not been widely used in industrial areas because overall it has low toughness and mechanical properties when compared to metals or ceramics. This research was conducted to produce geopolymer composite material with good mechanical properties and can be applied as a material in making environmentally friendly pipes, by identifying the influence of the composition of the geopolymer base material using the Taguchi method. Generate Geopolymer composites with the addition of Silica Powder and random short carbon fiber have good mechanical properties, from the results of the experiment produced the best flexural strength in T9 specimens with details of the composition of Silica Powder (27 g), Kaolin (55 g), CaO (6 g), and Carbon Fiber (13 gr) with a flexural strength of 41.46924655 MPa and flexural modulus 6 GPa.