复式火山（Stratovolcano），又称为成层火山、层状火山，是一个锥形火山，是由硬化的熔岩，火山喷发碎屑，浮岩和火山灰的许多层（阶层）不断堆积形成的。与盾状火山不同，复式火山的特点是陡峭的轮廓和周期性爆炸式火山喷发和喷溢式火山喷发，虽然有些已经崩溃的火山口被称为破火山口。从层火山流出的熔岩黏滞性较高，通常在冷却和蔓延远处之前就硬化。岩浆形成的熔岩往往是长英质，具有高至中等水平二氧化硅（如流纹岩，英安岩，或安山岩），还有少量的不太粘稠的镁铁质火成岩岩浆。大量的长英质熔岩流并不常见，但是已有流淌到最远处达15 km（9.3 mi）.

A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic explosive eruptions and effusive eruptions, although some have collapsed craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far due to high viscosity. The magma forming this lava is often felsic, having high-to-intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less-viscous mafic magma. Extensive felsic lava flows are uncommon, but have travelled as far as 15 km (9.3 mi).